LIGO/Virgo S190425z
GCN Circular 24167
Subject
LIGO/Virgo S190425z Global MASTER-Net observations report
Date
2019-04-25T09:32:31Z (6 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa,
A.Kuznetsov, V.V.Chazov, D. Vlasenko
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory
K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk
Irkutsk State University
V. Yurkov, A. Gabovich, Yu. Sergienko
Blagoveschensk Educational State University, Blagoveschensk
R. Podesta, Carlos Lopez and F. Podesta
Observatorio Astronomico Felix Aguilar (OAFA)
Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias
D. Buckley, S. Potter, A. Kniazev, M. Kotze
South African Astronomical Observatory
MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the LIGO/Virgo S190425z errorbox 3133 sec after trigger time at 2019-04-25 09:10:18 UT, with upper limit up to 17.9 mag. The observations began at zenit distance = 80 deg. The sun altitude is -24.3 deg.
The galactic latitude b = -60 deg., longitude l = 98 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/ligo_1.php?id=10197
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
3224 | 2019-04-25 09:10:18 | MASTER-OAFA | ( 16h 8m 58.30s , +22d 53m 12.75s) | C | 180 | 17.7 |
3482 | 2019-04-25 09:14:36 | MASTER-OAFA | ( 16h 8m 58.90s , +22d 53m 17.07s) | C | 180 | 17.9 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 24168
Subject
LIGO/Virgo S190425z: Identification of a GW compact binary merger candidate
Date
2019-04-25T09:53:13Z (6 years ago)
From
Leo Singer at GSFC <leo.p.singer@nasa.gov>
The LIGO Scientific Collaboration and the Virgo Collaboration report:
We identified the compact binary merger candidate S190425z during
real-time processing of data from LIGO Livingston Observatory (L1) and
Virgo Observatory (V1) at 2019-04-25 08:18:05.017 UTC (GPS time:
1240215503.017). The candidate was found by the GstLAL [1] and PyCBC
Live [2] analysis pipelines.
The signal-to-noise ratio (SNR) was below threshold in V1 so the
candidate was treated as a single-instrument event and no automated
preliminary notice was sent. Nonetheless, the V1 SNR is consistent
with the L1 data given the relative sensitivities of the detectors.
LIGO Hanford Observatory (H1) was offline at the time.
S190425z is an event of interest because its false alarm rate as
estimated by the online analysis is 4.5e-13 Hz, or about one in 7e4
years. The event's properties can be found at this URL:
https://gracedb.ligo.org/superevents/S190425z
The classification of the GW signal, in order of descending
probability, is BNS (>99%), Terrestrial (<1%), NSBH (<1%), BBH (<1%),
or MassGap (<1%).
Assuming the candidate is astrophysical in origin, there is strong
evidence for the lighter compact object having a mass < 3 solar masses
(HasNS: >99%). Using the masses and spins inferred from the signal,
there is strong evidence for matter outside the final compact object
(HasRemnant: >99%).
One skymap is available at this time and can be retrieved from the
GraceDB event page:
* bayestar.fits.gz, an initial localization generated by BAYESTAR [3],
distributed via GCN notice about 42 minutes after the candidate.
For the bayestar.fits.gz skymap, the 90% credible region is 10183
deg2. Marginalized over the whole sky, the a posteriori luminosity
distance estimate is 155 +/- 45 Mpc (a posteriori mean +/- standard
deviation). The skymap is coarser than usual due to the low
signal-to-noise ratio in V1; the localization is dominated by the L1
antenna pattern.
For further information about analysis methodology and the contents of
this alert, refer to the LIGO/Virgo Public Alerts User Guide
<https://emfollow.docs.ligo.org/userguide/>.
[1] Messick et al. PRD 95, 042001 (2017)
[2] Nitz et al. PRD 98, 024050 (2018)
[3] Singer & Price PRD 93, 024013 (2016)
GCN Circular 24169
Subject
LIGO/Virgo S190425z: INTEGRAL prompt observation
Date
2019-04-25T10:03:31Z (6 years ago)
From
Antonio Martin-Carrillo at UCD,Space Science Group <antonio.martin-carrillo@ucd.ie>
A. Martin-Carillo (UCD, Dublin)
V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland)
J. Rodi (IAPS-Roma, Italy)
A. Coleiro (APC, France)
S. Mereghetti (INAF IASF-Milano, Italy)
on behalf of the INTEGRAL multi-messenger collaboration:
https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration
We investigated serendipitous INTEGRAL observations carried out at the
time of the LIGO/Virgo burst candidate S190425z. The satellite was
covering the entire localization region of the LIGO-Virgo event with a sensitivity depending on the source position.
The best sensitivity depends on the source location.
We investigated the SPI-ACS and IBIS/PICsIT light curves between -30 and +30 s from
the trigger time (2019-04-25T08:18:05 UTC, T0) on temporal scales from
0.1 to 10s.
In the SPI-ACS or IBIS/PICsIT data, we do not detect a significant signal.
In SPI-ACS data, a marginally significant excess with S/N of 3.7 at is seen at T0+6s at the timescale of 1s.
Further analysis is ongoing, and will be reported in the coming circulars.
https://www.astro.unige.ch/cdci/integral/transients/lvc-s190425z
GCN Circular 24170
Subject
LIGO/Virgo S190425z: INTEGRAL SPI-ACS prompt observation
Date
2019-04-25T10:27:09Z (6 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
P. Minaev, A. Pozanenko, S. Grebenev, I. Chelovekov on behalf of IKI GRB FuN collaboration report:
We used public data of SPI-ACS to perform a search for possible EM-counterpart of LIGO/Virgo S190425z. Here we report preliminary analysis of SPI-ACS data available. After trigger time of S190425z (G330561) we found two pulses with time since trigger, duration, significance and fluence (in counts) above a background as following
+0.5 s, 0.4 s, 3.6 sigma, 900 +/- 250
+6 s, 1 s, 4 sigma, 1620 +/- 400
The significance of the second pulse is somewhat larger in comparison with reported early in GCN 24169 (Martin-Carillo et al.)
We estimated fluence of first and second pulses in the energy range 75 - 1000 keV as (9.0 +- 0.3) * 10^-8 erg/cm2 and (1.6 +- 0.4 ) * 10^-7
erg/cm2, respectively. It corresponds to E_iso (2.5 +/- 0.7) * 10^47 erg and (4.5 +/- 1.1) * 10^47 erg assuming distance 154.6 Mpc.
We do no found any extended emission up to T0+270 s after trigger.
The boresight of the center of the eror box localization (RA, Dec 16 10
18.75, 22 49 53.0609) is about 31 degrees.
GCN Circular 24171
Subject
LIGO/Virgo S190425z: Potential host galaxies from the GLADE catalog
Date
2019-04-25T10:28:06Z (6 years ago)
From
Gergely Dalya at Eotvos U <dalyag@caesar.elte.hu>
Gergely D��lya and Peter Raffai (Eotvos Univ.) reports on behalf of the
GLADE team:
We have found 45,033 galaxies in the GLADE catalog [1], within the 90% GW
localization area reported by the LVC in GCN 24168, and within 155 +/- 45
Mpc
distance limits.
The galaxies found can be accessed on the GLADE website (12 MB txt file;
please note that the order of galaxies in the list only follow the ordering
as the appear in GLADE):
http://glade.elte.hu/O3/S190425z_GLADE_90_1sigma.txt
There are 13,330 galaxies within the 50% GW localization area and within
the same distance limits (3.6 MB txt file; please note that the order of
galaxies in the list only follow the ordering as the appear in GLADE):
http://glade.elte.hu/O3/S190425z_GLADE_50_1sigma.txt
[1] D��lya, G., Galg��czi G., Dobos, L. et al., 2018 MNRAS, 479, 2374
GCN Circular 24172
Subject
LIGO/Virgo S190425z: SAGUARO follow-up observations
Date
2019-04-25T10:59:32Z (6 years ago)
From
Michael J. Lundquist at University of Arizona <mlundquist@email.arizona.edu>
Michael J. Lundquist (UA), Kerry Paterson, Wen-fai Fong (Northwestern),
David J. Sand (UA), Stefano Valenti (UC Davis), Sheng Yang (INAF-OAPd, UC
Davis), Sam Wyatt (UA), Eric Christensen, Alex Gibbs, Frank Shelly
(UA/LPL), Jennifer Andrews (UA) report:
We initiated observations of 12 fields (each 2.26 x 2.26 deg^2) within the
LVC localization region for the GW trigger S190425z (LVC Circ 24168)
starting on 2019-04-25 9:01 UT. SAGUARO* uses the 1.5m Catalina Sky Survey
telescope on Mt. Lemmon, AZ and its 5 deg^2 imager to tile the highest
probability regions of the LVC localization that are accessible from
southern Arizona in order to search for electromagnetic counterparts to
gravitational wave events. The typical limiting magnitudes of single
pointings are G~21 mag (calibrated to Gaia DR2). Below are the field
centers observed. Any interesting transient candidates will be reported as
soon as possible.
RA DEC
244.2855 20.9792
245.7690 18.7708
247.2150 16.5625
242.7630 23.1875
240.4020 25.3958
237.9450 27.6042
235.4790 27.6042
237.9870 25.3958
240.3945 23.1875
247.9245 14.3541
249.3165 12.1458
235.3845 29.8125
*SAGUARO stands for Searches After Gravitational-waves Using ARizona's
Observatories. It is a partnership between the University of Arizona and
Northwestern University.
GCN Circular 24173
Subject
LIGO/VirgoS190425z: HAWC follow-up
Date
2019-04-25T11:16:41Z (6 years ago)
From
Harm Schoorlemmer at MPIK, HAWC <harmscho@mpi-hd.mpg.de>
The HAWC Collaboration (https://www.hawc-observatory.org) reports:
The HAWC Collaboration performed a follow-up of the gravitational wave
trigger S190425z (GCN #24168). At the time of the trigger the HAWC
local zenith was oriented towards (RA, Dec) = (240.1deg, 19.0deg).
48% of the GW candidate sky location probability fell within our
observable field of view (0-45 deg zenith angle).
We performed a search for a short timescale emission using 6 sliding
time windows (dt = 0.3s, 1s, 3s, 10s, 30s and 100s), shifted forward
in time by 20% of their width. We searched the 95% probability
containment area in a timescale-dependent time period, from t0-5dt to
t0+10dt, where t0 is the time of the GW trigger.
No significant gamma-ray detection above the background was observed.
The sensitivity of this analysis is greatly dependent on zenith angle,
ranging from 0deg to 45deg for the area searched in this
analysis. The 5sigma detection sensitivity to a 1s (100s) burst in the
80-800GeV energy range goes from 1.2e-6 erg/cm^2 to 1.1e-4 erg/cm^2
(6.4e-6 erg/cm^2 to 5.0e-4 erg/cm^2), depending on the zenith
angle.
HAWC is a TeV gamma ray water Cherenkov array located in the state of
Puebla, Mexico. It is sensitive to the energy range ~0.1-100TeV, and
monitors 2/3 of the sky every day with an instantaneous field-of-view
of ~2 sr.
On behalf of the HAWC collaboration.
Harm Schoorlemmer
Postdoctoral Researcher,
Max-Planck-Institut f��r Kernphysik,
Saupfercheckweg 1,
69117 Heidelberg,
Germany
phone +49 (0)6221 516 145
GCN Circular 24175
Subject
LIGO/Virgo S190425z: Hobby-Eberly Telescope VIRUS observations of target galaxies.
Date
2019-04-25T11:51:47Z (6 years ago)
From
J. Craig Wheeler at U.Texas Austin <wheel@astro.as.utexas.edu>
M. J. B. Rosell, Matthew Shetrone, J. Craig Wheeler, Aaron Zimmerman, Chad Hanna, Lifan Wang, Greg Zeimann, and Richard Matzner on behalf of the LIGO Hobby-Eberly Telescope Response (LIGHETR) team report the spectroscopic observation of the field of S190425z (GCN #24168) with the VIRUS IFU array. We sampled a prioritized list of 5 galaxies from the GLADE catalog that overlapped with the LIGO probability map and the observable pupil of the HET. The resulting data cube covers the wavelength 350 to 550 nm with a resolving power of 750. The effective limiting magnitude in the B band was 22 magnitudes. Each field is 50x50 arc seconds. We observed, in order, galaxies:
254.780334-5.741986
254.505371-1.822693
253.245255+2.400985
241.236267+23.932871
247.400574+15.658440
Report of the results will be submitted later.
--
J. Craig Wheeler
Samuel T. and Fern Yanagisawa Regents Professor of Astronomy
University and University of Texas System Distinguished Teaching Professor
President, American Astronomical Society, 2006-2008
Department of Astronomy
2515 Speedway, Stop C1400
Austin, TX 78712-1205
512-471-6407
http://www.as.utexas.edu/~wheel
Supernova Explosions http://www.springer.com/us/book/9783662550526
Cosmic Catastrophes http://ebooks.cambridge.org/ebook.jsf?bid=CBO9780511536625
The Krone Experiment Krone Ascending http://www.amazon.com/Krone-Ascending-ebook/dp/B00926QEGW
GCN Circular 24177
Subject
LIGO/Virgo S190425z: MAXI/GSC Observations
Date
2019-04-25T12:50:24Z (6 years ago)
From
Mutsumi Sugizaki at Tokyo Tech./MAXI <sugizaki.mutsumi@gmail.com>
M. Sugizaki, N. Kawai (Tokyo Tech), H. Negoro (Nihon U.),
M. Serino, S. Sugita (AGU),
M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi (Nihon U.),
S. Nakahira, T. Mihara, T. Tamagawa, M. Matsuoka (RIKEN),
T. Sakamoto, H. Nishida, A. Yoshida (AGU),
Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, T. Sato (Chuo U.),
M. Shidatsu (Ehime U.), M. Oeda, K. Shiraishi (Tokyo Tech),
S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, N. Isobe, R. Shimomukai,
M. Tominaga (JAXA),
Y. Ueda, A. Tanimoto, T. Morita, S. Yamada, S. Ogawa (Kyoto U.),
H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.),
M. Yamauchi, S. Iwahori, Y. Kurihara (Miyazaki U.),
T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU)
report on behalf of the MAXI team:
We examined the MAXI/GSC all-sky X-ray images (2-20 keV) obtained
in the orbit after the LVC trigger
S190425z at 2019-04-25 08:18:05.017 UTC (GCN 24168).
At the trigger time of S190425z, the high-voltage of MAXI/GSC was off,
and it was turned on at T0+1054 sec (=T0+17.5 min).
The one-orbit (92 min) scan of GSC covered > 90% of the 90% error region
of the bayestar skymap from 08:35:39 to 09:50:05 UTC (T0+1054 to T0+5520 sec).
No significant new source was found in the error region at the one-orbit scan.
The 1-sigma averaged upper limit obtained
from the scan was 20 mCrab at 4-10 keV.
If you require information of X-ray flux by MAXI/GSC at specific coordinates,
please contact the submitter of this circular by email.
GCN Circular 24178
Subject
LIGO/Virgo S190425z: further analysis of INTEGRAL data
Date
2019-04-25T13:06:11Z (6 years ago)
From
Volodymyr Savchenko at ISDC,U of Geneve <savchenk@in2p3.fr>
V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland)
A. Martin-Carillo (UCD, Dublin)
J. Rodi (IAPS-Roma, Italy)
A. Coleiro (APC, France)
S. Mereghetti (INAF IASF-Milano, Italy)
on behalf of the INTEGRAL multi-messenger collaboration:
https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration
We detect only one possible low-S/N excess after correcting
for the local background variance at 2019-04-25T08:18:05
(T0)+6s, as reported in Martin-Carillo 2019 (GCN 24169).
Its fluence strongly depends on the true source location,
since large 90% localization region provided by LIGO/Virgo
includes sky directions in which INTEGRAL detectors able to
detect impulsive signal from all-sky (SPI-ACS and IBIS)
featured both low and high sensitivity.
For the excess at T0+6s, we estimate a possible 75-2000 keV
fluence range due to uncertainty of the location
from 2.0e-10 to 2e-9 erg/cm2 (in addition to systematic
uncertainty of response of 20% and statistical uncertainty of 30%),
assuming the duration of 1s and a characteristic short GRB spectrum
(an exponentially cut off power law with alpha=-0.5 and Ep=600 keV).
The sensitivity map is provided:
https://www.astro.unige.ch/cdci/content/int-combined-sensitivity-map-lvc-s190425z
We stress that the FAP of association of this excess to S190425z
is below 3 sigma. Further estimate of the FAP, taking into account detail
noise estimates during the days around the event, will be
provided in the future publications.
INTEGRAL is unable to provide an accurate localization of
the above mentioned low-S/N excess.
The best localization constraint we are currently able to
provide excludes the FoV of INTEGRAL/IBIS at the time of the event
(18:24:43.61, +29:45:25.9, 15 deg radius).
An event comparable to the excess at T0+6s occurring in the FoV
would have been detected by INTEGRAL/IBAS in realtime.
Furthermore, a location close to the FoV (within ~30 deg
from the center of the pointing) is discouraged by the lack
of INTEGRAL IBIS/PICsIT detection.
The south-west arc of the LIGO/Virgo localization of S190425z
is slightly unfavorable for the origin of the low-S/N excess,
if it is associated with the GW signal due to the absence
of any signal in IBIS/Veto shield.
Further analysis will be reported in the following circulars.
INTEGRAL has initiated a target of opportunity observation
of S190425z centered near peak of the LIGO/Virgo localization.
The results of these observations will be reported in
upcoming publications.
GCN Circular 24179
Subject
LIGO/Virgo S190425z: Lick/KAIT Follow-Up Observations
Date
2019-04-25T13:12:40Z (6 years ago)
From
Weikang Zheng at UC Berkeley <weikang@berkeley.edu>
WeiKang Zheng, Keto Zhang, Sergiy Vasylyev and Alexei V. Filippenko
(UC Berkeley) report on behalf of the Lick/KAIT GW follow-up team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, observed the field of the gravitational-wave event
S190425z (GCN 24168) detected by LIGO/Virgo. More than one thousand
galaxies were selected from the Glade catalog (V1.0)
(http://aquarius.elte.hu/glade/)
according to their priority score. KAIT observed 101 of them based on
their priority scores and elevation visibility, with each clear-filter
exposure time being 60 s. The first image was taken at 09:06:22, Apr. 25 UT,
about 48 minutes after the trigger, and the last image at 12:43:52 UT.
Our typical limiting mag is 19.0. No viable counterparts were identified
and the analysis is ongoing. A full list of galaxies observed by KAIT is
given below.
GladeID UT(Apr. 25) RA (J2000) Dec
-----------------------------------------------
G0613278 09:06:22 16:56:00.440 -16:58:54.80
G0628454 09:07:32 16:51:59.390 -15:02:08.50
G0609502 09:08:41 16:54:11.660 -16:19:16.90
G0748918 09:09:52 16:55:11.420 -07:39:56.40
G0667530 09:11:04 16:50:28.100 -17:40:35.60
G0757013 09:12:17 17:00:09.120 -05:46:12.50
G0559558 09:13:28 16:53:14.560 -17:05:05.10
G0585341 09:14:45 17:36:45.540 -07:42:16.50
G0726908 09:16:01 16:58:16.410 -06:15:33.60
G1850976 09:17:15 16:59:15.230 -21:18:09.90
G0590730 09:18:29 16:47:04.560 -23:29:07.70
G0276771 09:19:52 16:10:41.090 +22:33:54.90
G1851040 09:21:09 16:50:55.320 +09:24:14.30
G1478254 09:22:28 16:59:14.830 -21:18:11.30
G0586459 09:23:46 17:01:57.300 -01:52:22.00
G0507438 09:25:13 14:49:14.020 +34:55:06.60
G0566010 09:26:40 16:58:00.170 -18:42:57.40
G0683517 09:28:03 15:48:33.540 +28:35:01.90
G0004443 09:29:25 16:50:10.830 -17:40:41.70
G0731963 09:30:41 16:43:02.640 -30:04:59.50
G0662464 09:32:07 15:41:23.410 +28:17:59.00
G0708649 09:33:21 16:35:15.560 +21:30:07.00
G1851754 09:34:33 16:25:27.940 +19:27:48.90
G0741008 09:35:51 17:03:03.210 -02:52:38.50
G0584664 09:37:02 16:53:57.180 +02:22:12.10
G0650210 09:38:14 16:59:27.080 -03:21:27.30
G0758227 09:39:23 17:01:49.730 -05:12:04.00
G0558432 09:40:54 14:25:08.900 +36:22:28.00
G0663901 09:42:19 15:42:41.990 +28:04:24.00
G0670888 09:43:43 16:51:40.710 -14:50:18.20
G1335365 09:45:21 16:50:29.870 +05:59:02.60
G1487455 09:46:40 16:48:32.800 -20:10:29.00
G1851713 09:48:00 16:04:43.040 +24:57:33.60
G0611033 09:49:21 17:23:59.070 +12:40:43.10
G0711803 09:50:36 16:49:18.270 +06:11:23.10
G0012977 09:51:53 16:12:20.000 +23:45:45.90
G0663460 09:53:02 16:15:48.000 +21:53:28.30
G0737278 09:54:12 16:18:57.820 +21:01:13.10
G0557323 09:55:25 16:48:32.110 +08:43:10.00
G0824857 09:56:39 16:10:54.830 +22:36:02.70
G0739581 09:57:48 16:05:48.750 +23:55:08.10
G0660247 09:59:13 16:43:04.750 -24:58:53.80
G0618875 10:00:51 16:52:18.760 -14:55:05.10
G0663276 10:02:15 15:41:36.340 +28:13:53.10
G0751587 10:03:24 15:37:46.100 +29:44:45.80
G0618341 10:04:57 12:25:58.470 +28:27:06.00
G0601575 10:06:38 17:22:45.260 -00:48:48.20
G0623602 10:07:56 16:25:05.890 +20:08:24.10
G0814957 10:09:12 15:46:17.560 +26:32:37.80
G0618315 10:10:24 16:09:40.390 +21:59:33.80
G0558317 10:11:35 15:48:25.170 +26:00:17.50
G0663689 10:12:50 16:26:30.500 +16:24:44.50
G0681192 10:14:00 16:26:42.480 +16:31:59.50
G0752198 10:15:16 17:04:28.120 -04:18:28.40
G0455861 10:16:35 16:17:53.830 +18:47:47.50
G0692311 10:17:46 16:05:24.260 +25:08:18.40
G0158036 10:19:08 15:32:24.450 +40:48:01.00
G0784470 10:20:38 12:33:40.290 +29:36:21.10
G0771147 10:22:20 16:58:44.220 +27:49:33.00
G0758446 10:23:41 15:53:10.080 +24:34:12.00
G0734770 10:25:14 12:36:06.560 +29:38:15.70
G0019288 10:26:37 14:30:49.240 +36:16:33.90
G0605492 10:28:04 16:13:21.730 +29:26:10.60
G0700806 10:29:39 12:16:35.990 +23:52:25.60
G0124335 10:31:21 17:05:50.250 -06:16:50.10
G0610913 10:32:30 17:07:51.900 -05:26:15.00
G0698486 10:34:15 15:56:34.510 +24:26:18.30
G0642511 10:36:00 16:08:29.500 +22:17:30.30
G0494340 10:37:31 14:17:19.150 +39:30:01.20
G0617925 10:39:06 17:06:04.150 -04:37:17.10
G0947437 10:40:49 12:42:40.510 +34:57:25.50
G0622172 10:42:29 16:52:32.920 -03:07:40.10
G0810215 10:43:41 17:11:22.040 -03:15:10.80
G0475468 10:44:54 16:50:21.360 -16:54:39.60
G0013985 10:46:41 16:52:24.580 -02:28:56.20
G0789194 10:48:03 16:29:18.110 +39:30:37.80
G0730444 10:49:41 13:36:05.390 +34:34:43.60
G0822150 10:51:18 17:23:18.040 +02:00:02.30
G1053682 10:52:27 17:06:00.430 -01:34:00.00
G0586726 10:53:49 16:04:49.280 +25:54:12.80
G1308107 10:55:43 17:43:53.840 -09:43:55.50
G0396851 10:56:59 17:02:23.190 +06:53:58.30
G0598298 10:58:48 17:34:27.070 -03:22:44.20
G0395107 11:00:40 16:05:18.810 +17:41:54.30
G1851796 11:01:57 17:01:39.100 +10:14:58.80
G0728968 11:03:31 14:18:00.840 +35:19:13.50
G0157871 11:05:03 16:51:04.200 +23:32:51.40
G0597368 11:07:16 13:33:38.920 +41:46:22.30
G0650943 11:09:10 16:22:09.820 +36:19:53.40
G0796244 11:10:19 16:25:49.280 +40:50:57.70
G0603545 12:25:59 17:28:53.300 +03:13:43.30
G0799222 12:27:11 17:44:20.570 -01:41:28.50
G1487440 12:28:28 16:33:24.450 -28:07:56.80
G0717723 12:29:58 16:15:09.240 +35:03:43.30
G0819110 12:31:07 16:07:12.140 +36:37:51.40
G0719827 12:32:31 17:09:42.030 +03:52:13.80
G0566209 12:33:46 16:42:10.440 +13:21:19.70
G0726358 12:35:04 17:14:45.210 -06:05:54.90
G1172942 12:36:13 17:10:39.300 -06:52:45.30
G0624001 12:41:50 17:13:35.090 -05:36:45.60
G0584919 12:43:52 16:29:45.830 +17:50:59.10
GCN Circular 24181
Subject
LIGO/Virgo S190425z: INTEGRAL IBIS prompt observation
Date
2019-04-25T14:19:28Z (6 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
I. Chelovekov, A. Pozanenko, P. Minaev, S. Grebenev on behalf of the IKI
GRB FuN collaboration report:
We used public data (observations of Inner Galaxy, proposal 1620021, PI
A. Bodaghee) of IBIS-ISGRI/INTEGRAL to search for a possible
EM-counterpart of the LIGO/Virgo S190425z event (LVC GCN #24168). We
present our preliminary analysis of the prompt off-axis observation of
the event with IBIS-ISGRI.
Around trigger time of S190425z (=G330561) the boresight angle was 30.8
degrees. We found no significant emission above the background in the
time window -100 s + 100 s around the LIGO/Virgo S190425z trigger time.
In particular, we did not detect any positive signal near the time of a
hard X-ray pulse detected by SPI-ACS/INTEGRAL(Martin-Carillo et al. GCN
#24169; Minaev et al., GCN #24170; Savchenko et al., GCN #24178).
The upper limit of any possible emission with a duration of 1 s was (1.7
+/- 0.8) x 10^{-6} erg / cm2 and (1.3 +/- 0.8) x 10^{-6} erg / cm2 in
the energy ranges 30-100 and 100-500 keV, respectively. To estimate the
flux we used our calibration based on several hundreds of GRBs
synchronously detected by GBM/Fermi and on/off-axis by IBIS/ISGRI
(Chelovekov et al, 2019, in press).
The light curves of IBIS/ISGRI and SPI-ACS can be found in
http://grb.rssi.ru/S190425z/S190425z_SPI-ACS.png
http://grb.rssi.ru/S190425z/S190425z_IBIS_1s.png
GCN Circular 24182
Subject
LIGO/Virgo S190425z: MMT Follow-Up Observations
Date
2019-04-25T14:26:34Z (6 years ago)
From
Griffin Hosseinzadeh at Harvard U <griffin.hosseinzadeh@cfa.harvard.edu>
G. Hosseinzadeh, E. Berger, P. K. Blanchard, T. Eftekhari, J. Gill,
S. Gomez, L. Patton, V. A. Villar, P. K. G. Williams (Harvard U),
P. S. Cowperthwaite (Carnegie Obs), R. Chornock (Ohio U), W. Fong,
R. Margutti (Northwestern U), and M. Nicholl (U Edinburgh) report:
We obtained 30 s g-band images of the following galaxies in the LIGO/Virgo
localization region of S190425z with the MMTCam instrument on the MMT 6.5-m
telescope:
Name R.A. Dec. Date UT
16545364-1657072 253.723525833333 -16.952021 2019-04-25 11:39:23.06
16571426-0613510 254.309417916667 -6.230837 2019-04-25 11:42:29.66
16520774-1703135 253.032287916667 -17.053755 2019-04-25 11:44:21.54
16590728-0544311 254.780334166667 -5.741986 2019-04-25 11:45:55.20
16580128-0149216 254.505370833333 -1.822693 2019-04-25 11:47:32.92
NGC6234 252.988937083333 4.383557 2019-04-25 11:49:28.05
59064 252.388167916667 6.016252 2019-04-25 11:51:21.12
59201 253.350372083333 4.23625 2019-04-25 11:52:39.44
16564688-0142052 254.195357916667 -1.701466 2019-04-25 11:54:11.67
UGC10426 247.709015 16.250687 2019-04-25 11:57:26.92
90265.0 254.36174 -10.191098 2019-04-25 11:59:13.75
NGC6225 252.08989 6.222765 2019-04-25 12:00:51.40
16462248+0902154 251.593704166667 9.037632 2019-04-25 12:02:05.10
16552449-0715255 253.852080833333 -7.25709 2019-04-25 12:04:56.52
Comparison of the images to the PS1 3pi survey (Chambers et al. 2016,
arXiv:1612.05560) reveals no new sources brighter than ~21 mag.
We thank Mike Calkins and Ben Kunk at MMT for taking these observations.
GCN Circular 24183
Subject
LIGO/Virgo S190425z: SQUEAN Observation
Date
2019-04-25T15:11:29Z (6 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
Myungshin Im (SNU), Gregory S. H. Paek (SNU), Gu Lim (SNU), Insu Paek
(SNU), Suhyun Shin (SNU), Joonho Kim (SNU), Soojong Pak (KHU), Sungyong
Hwang (SNU), Bomi Park (SNU), Sophia Kim (SNU), Changsu Choi (SNU),
Chung-Uk Lee (KASI), Seung-Lee Kim (KASI), Hyung Mok Lee (KASI), on behalf
of a larger collaboration
We observed 30 host galaxy candidates in the 90% localization area of the
BNS merger candidate, S190425z, detected by LIGO/Virgo (GCN #24168) using
the SQUEAN instrument on the McDonald observatory's 2.1m telescope. The
observation started at 2019-4-25 09:38:57 UT, and the images were taken in
i-band with 120 sec exposure time. No obvious transient has been identified
to a preliminary 3-sigma depth of i=20.0 AB mag. The list of the inspected
targets is given below.
NAME RA DEC
IC4587 239.965057 25.940653
UGC10153 240.83136 20.636812
UGC10320 244.530502 21.066381
PGC58097 246.408646 16.455
2MASS+16590728-0544311 254.780334 -5.741986
UGC10016 236.370865 26.603144
PGC55801 235.374939 27.986473
PGC55774 235.152664 28.512449
2MASS+16585063-1557280 254.710999 -15.957801
2MASS+16582619-0319463 254.609146 -3.329548
2MASS+17004803-0510264 255.200165 -5.17402
2MASS+16572382-0147498 254.349258 -1.797175
2MASS+16574955-0156027 254.456467 -1.934085
2MASS+17030866-0237020 255.786118 -2.617223
2MASS+16550989+0551321 253.791245 5.858919
2MASS+16540875-0738073 253.536499 -7.635365
UGC10678 255.993729 24.177513
PGC58992 251.901932 8.752961
PGC1470081 247.533737 14.903552
PGC57472 243.084732 23.001947
PGC1688132 240.935242 23.482073
NGC6097 243.608948 35.109116
NGC5567 214.823303 35.138004
PGC51918 217.984253 33.642612
PGC1277972 252.051498 5.089275
PGC1112217 255.254517 -1.705736
IC1255 260.77243 12.69542
6dFJ1654568-153135 253.736633 -15.526299
2MASS+16520774-1703135 253.032288 -17.053755
PGC59300 254.266769 5.372032
GCN Circular 24184
Subject
LIGO/Virgo S190425z: Swift/BAT Counterpart Search
Date
2019-04-25T15:18:44Z (6 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
T. Sakamoto (AGU), S. D. Barthelmy (NASA/GSFC),
A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
A. A. Breeveld (MSSL-UCL), A. P. Beardmore (U. Leicester),
D. N. Burrows (PSU), S. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC),
G. Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA),
P. D'Avanzo (INAF-OAB), V. D'Elia(ASDC), S. Emery (UCL-MSSL),
P. A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU),
D. Hartmann (Clemson U.), J. A. Kennea (PSU), H. A. Krimm (NSF),
N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), B. Mingo (U. Leicester), J. A. Nousek (PSU),
S. R. Oates (Uni. of Warwick), P. T. O'Brien (U. Leicester),
J. P. Osborne (U. Leicester), C. Pagani (U. Leicester),
K. L. Page (U.Leicester), M. Perri (ASDC),
J. L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU),
M. H. Siegel (PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (PSU),
E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team:
We report the search results in the BAT data within T0 +/- 100 s of the
LVC event S190425z (LIGO/VIRGO Collaboration GCN Circ. 24168),
where T0 is the LVC trigger time (2019-04-25T08:18:05.000 UTC).
The center of the BAT FOV at T0 is
RA = 123.263 deg,
DEC = 22.657 deg,
ROLL = 279.608 deg.
The BAT Field of View (>10% partial coding) covers 7.26% of the integrated
LVC localization probability, and 5.31% of the galaxy convolved
probability (Evans et al. 2016).
Within T0 +/- 100 s, no significant detections (signal-to-noise ratio
>~ 5 sigma) are found in the BAT raw light curves with time bins of 64 ms,
1 s, and 1.6 s. Assuming an on-axis (100% coded) short GRB with
a typical spectrum in the BAT energy range (i.e., a simple power-law model
with a power-law index of -1.32, Lien & Sakamoto et al. 2016), the 5-sigma
upper limit in the 1-s binned light curve corresponds to a flux upper limit
(15-350 keV) of ~ 8.01 x 10^-8 erg/s/cm^2.
No event data are available at this time.
BAT retains decreased, but significant, sensitivity to rate increases for
gamma-ray events outside of its FOV. About 45.73% of the integrated LVC
localization probability was outside of the BAT FOV but above the
Earth's limb from Swift's location, and the corresponding flux upper limits
for this region are within roughly an order of magnitude higher of those
within the FOV.
The results of the BAT analysis are available at
https://swift.gsfc.nasa.gov/results/BATbursts/team_web/S190425z/web/source_20190425.html
GCN Circular 24185
Subject
LIGO/Virgo S190425z: Fermi GBM Observations
Date
2019-04-25T15:35:23Z (6 years ago)
From
Cori Fletcher at USRA/NASA <corinne.l.fletcher@nasa.gov>
C. Fletcher (USRA) reports on behalf of the Fermi-GBM Team and the
GBM-LIGO/Virgo group:
For S190425z and using the initial BAYESTAR skymap, Fermi-GBM was
observing 55.6% of the probability region at event time.
There was no Fermi-GBM onboard trigger around the event time of
the LIGO/Virgo detection of GW trigger S190425z (GCN 24168).
An automated, blind search for short gamma-ray bursts below the
onboard triggering threshold in Fermi-GBM also identified no
counterpart candidates. The GBM targeted search, the most
sensitive, coherent search for GRB-like signals, was run from
+/-30 s around merger time, and also identified no counterpart
candidates.
Assuming a detectable relativistic jet, it likely originated from the
44% of the LVC localization behind the Earth for Fermi, located at
RA=194.64, Dec=22.47 with a radius of 67.2 degrees. This region is
also consistent with the highest probability density region of the
BAYESTAR map. Otherwise, we set the following upper limits for the
remaining 90% localization region not blocked by the Earth. Using
the representative soft, normal, and hard GRB-like spectral templates
described in arXiv:1612.02395, we set the following 3 sigma flux
upper limits over 10-1000 keV (in units of 10^-7 erg/s/cm^2):
Timescale Soft Normal Hard
------------------------------------
0.1 s: 4.2-117 8.8-84. 27.-93.
1.0 s: 1.3-35. 2.7-25. 7.8-28.
10 s: 0.4-11. 0.9-7.7 2.4-8.7
Assuming the mean luminosity distance of ~155 Mpc from the GW
detection, we estimate intrinsic luminosity upper limits of
(0.03-5.1)E49 erg/s for the soft template, (0.04-3.4e)E49 erg/s
for the normal template, and (0.2-6.2)E49 erg/s for the hard template
over the 1 keV-10 MeV energy range.
GCN Circular 24186
Subject
LIGO/Virgo S190425z: AGILE-GRID Observations
Date
2019-04-25T15:41:12Z (6 years ago)
From
Giovanni Piano at INAF-IAPS <giovanni.piano@inaf.it>
G. Piano, C. Casentini (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), A.
Ursi, M.Cardillo (INAF/IAPS), M. Tavani (INAF/IAPS, and Univ. Roma Tor
Vergata), F. Lucarelli, C. Pittori (SSDC, and INAF/OAR), A. Bulgarelli, N.
Parmiggiani (INAF/OAS-Bologna), M. Pilia (INAF/OA-Cagliari), F. Longo
(Univ. Trieste, and INFN Trieste),
report on behalf of the AGILE Team:
In response to the LIGO-Virgo GW event S190425z at T0 = 2019-04-25 08:18:05
(UT), we performed a preliminary analysis of the AGILE Gamma-Ray Imaging
Detector (GRID). We divided the LIGO/Virgo localization region (LR) 90%
c.l. into two parts:
the first with R.A. in the approximate range between 1 - 8 hr, the second
with R.A. in the approximate range between 12 - 20 hr.
For the first part of the LR, we analyzed the first interval available with
a good coverage, between T0+100s and T0+200s. In this time interval, the
GRID exposure covered nearly 60% of the first part of the LR, observed at
off-axis angles between 25 deg and 70 deg. An analysis of the data in the
energy range 50 MeV - 10 GeV in this integration time was performed and
preliminary 3-sigma upper limits (ULs) values within the accessible
LIGO/Virgo LR are: from 4.1e-8 erg cm^-2 s^-1 to 4.5e-7 erg cm^-2 s^-1 for an
integration time of 100s.
In the time interval between T0-200 and T0+300, the GRID exposure covered
nearly 100% of the first part of the LR, observed at off-axis angles between
0 deg and 70 deg. An analysis of the data in the energy range 50 MeV - 10
GeV in this integration time was performed and preliminary 3-sigma ULs are:
from 1.4e-8 erg cm^-2 s^-1 to 3.2e-8 erg cm^-2 s^-1 for an integration time
of 500s.
Between T0+700s and T0+800s the GRID exposure covered nearly 15% of the
second part of the LR, observed at off-axis angles between 40 deg and 70
deg. An analysis of the data in the energy range 50 MeV - 10 GeV in this
integration time was performed and preliminary 3-sigma ULs are: from 4.2e-8
erg cm^-2 s^-1 to 2.3e-7 erg cm^-2 s^-1 for an integration time of 100s.
In the time interval between T0+700 and T0+2000, the GRID exposure covered
nearly 95% of the second part of the LR, observed at off-axis angles
between 40 deg and 70 deg. An analysis of the data in the energy range 50
MeV - 10 GeV in this integration time was performed and preliminary 3-sigma
ULs are: from 7.8e-9 erg cm^-2 s^-1 to 4.3e-8 erg cm^-2 s^-1 for an
integration time of 1300s.
These measurements were obtained with AGILE observing a large portion of
the sky in spinning mode.
GCN Circular 24187
Subject
LIGO/Virgo S190425z: Palomar Gattini-IR wide-field infrared follow-up
Date
2019-04-25T16:07:13Z (6 years ago)
From
Mansi M. Kasliwal at Caltech/Carnegie <mansikasliwal@gmail.com>
K. De (Caltech), S. M. Adams (Caltech), M. Coughlin (Caltech), M. M.
Kasliwal (Caltech), M. Hankins (Caltech), I. Andreoni (Caltech), S. Anand
(Caltech), L. Singer (NASA GSFC), , T. Ahumada (UMD), A. Moore (ANU), J.
Soon (ANU), M. Ashley (UNSW), T. Travouillon (ANU)
report on behalf of the Palomar Gattini-IR team and the larger GROWTH
(Global Relay of Observatories Watching Transients Happen) collaboration
We report wide-field near-infrared follow-up observations of the
localization region of the BNS gravitational wave event S190425z (GCN
24168) by the Palomar Gattini-IR survey (Moore and Kasliwal 2019).
Gattini-IR is a newly commissioned near-IR camera with a field of view of
25 square degrees mounted on a robotic 30 cm telescope at Palomar
observatory.
Gattini-IR was already observing the GW localization region as part of
routine survey operations at the time of the trigger. We started customized
Target of Opportunity observations at UT 2019-04-25 09:12:09 (11 minutes
after initial notice time). The tiling was optimally determined and
triggered using the GROWTH Target of Opportunity marshal (Coughlin et al.
2019a, Kasliwal et al. 2019b). We imaged a total of 2401 square degrees,
covering 31% of the probability region of the event. Each field visit
consisted of a sequence of 8 dithers of 8 second exposures each on the
field, which were processed and stacked with the Palomar Gattini-IR data
reduction pipeline (De et al., in prep.). The typical limiting magnitude of
each stacked epoch (64 second exposure time) was between 15.5 - 16 AB mag
in J-band. Transient vetting is ongoing and any viable counterparts will be
announced.
GCN Circular 24188
Subject
LIGO/Virgo S190425z: LOAO Observation
Date
2019-04-25T16:15:13Z (6 years ago)
From
Gregory SungHak Paek at SNU <shpaek@astro.snu.ac.kr>
Gregory S.H. Paek (SNU), Myungshin Im (SNU), Gu Lim (SNU), Insu Paek (SNU),
Suhyun Shin (SNU), Joonho Kim (SNU), Soojong Pak (KHU), Sungyong Hwang
(SNU), Bomi Park (SNU), Sophia Kim (SNU), Changsu Choi (SNU), Chung-Uk Lee
(KASI), Seung-Lee Kim (KASI), Hyung Mok Lee (KASI), on behalf of a larger
collaboration
We observed 13 host galaxy candidates with the 1.0-m telescope at the
Lemonsan Optical Astronomical Observatory(LOAO) in the 90% localization
area of S190425z, detected by LIGO/Virgo (GCN #24168).
The observation started at 2019-04-25 10:17:06 UT, and the images were
taken in R-band with 60 sec exposure time. No obvious transient has been
identified to a preliminary 3-sigma depth of R=19 AB mag. The list of the
inspected targets is given below.
NAME RA DEC
IC4587 239.965057 25.940653
2MASS+16582619-0319463 254.609146 -3.329548
PGC58097 246.408646 16.455
2MASS+17030866-0237020 255.786118 -2.617223
PGC55774 235.152664 28.512449
2MASS+16585063-1557280 254.710999 -15.957801
2MASS+17004803-0510264 255.200165 -5.17402
PGC55801 235.374939 27.986473
PGC1470081 247.533737 14.903552
NGC5567 214.823303 35.138004
UGC10320 244.530502 21.066381
2MASS+16590728-0544311 254.780334 -5.741986
UGC10016 236.370865 26.603144
GCN Circular 24190
Subject
LIGO/Virgo S190425z: Xinglong/Schmidt follow-up observations
Date
2019-04-25T16:21:40Z (6 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Dong Xu, Zi-Pei Zhu, Bang-Yao Yu, Tian-Meng Zhang, Xu Zhou, Xiao-Ming
Teng, Peng-Fei Liu, Xiang-Nan Guan (NAOC), Sheng Yang (INAF-OAPd),
Hai-Bin Zhao, Bin Li (PMO), Jin-Zhong Liu, Hu-Biao Niu, Jun-Hui Liu,
Xuan Zhang (XAO), Ji-Rong Mao, Jin-Ming Bai (YNAO), Xing Gao (Urumqi
No.1 Senior High School) report on behalf of the GWFUNC
collaboration:
We performed the search for the optical counterpart of LIGO/Virgo
S190425z (GCN 24168) using the 0.9-m Schmidt telescope located at
Xinglong, Hebei, China. Observations started at 12:40:09 UT on
2019-04-25 and ended at 13:42:18 UT on 2019-04-25, and the 1.5 x 1.5
deg^2 imager scanned high probability regions of the LVC localization
that are accessible to the Xinglong/Schmidt telescope. The unfiltered
images were taken with 60 sec exposure time and typical limiting depth
is around 18 mag.
The searching was stopped by growing heavy clouds. Listed below are the
field centers
observed.
RA(J2000) DEC(J2000)
15:01:34.100 +29:55:26.00
15:01:29.990 +31:25:33.00
15:01:30.100 +32:55:36.00
15:08:22.990 +29:55:27.00
15:08:33.290 +31:25:29.00
15:08:37.090 +32:55:24.00
15:15:20.500 +29:55:46.00
15:15:34.890 +31:25:28.00
15:15:40.000 +32:54:55.00
14:43:21.790 +34:25:01.00
14:43:19.900 +35:54:50.00
14:43:19.590 +37:24:42.00
14:50:26.690 +34:25:58.00
14:50:44.790 +35:55:17.00
14:50:38.800 +37:24:51.00
14:57:44.190 +34:25:15.00
14:58:09.000 +35:55:29.00
14:58:07.900 +37:25:22.00
15:22:27.600 +29:55:45.00
15:22:37.500 +31:25:34.00
15:22:37.190 +32:55:04.00
15:29:39.890 +29:55:55.00
15:29:35.400 +31:26:06.00
15:29:39.600 +32:55:48.00
14:21:09.600 +34:24:48.00
14:21:03.590 +35:54:44.00
14:21:05.100 +37:24:14.00
14:28:32.890 +34:24:47.00
14:28:31.000 +35:54:32.00
14:28:30.400 +37:24:52.00
14:35:40.790 +34:24:50.00
14:35:55.700 +35:54:37.00
14:35:56.300 +37:23:56.00
15:06:26.900 +34:25:18.00
15:06:06.990 +35:55:32.00
Data analysis is ongoing. Optical transient(s) from the above fields, if
interesting, will be
reported later.
GCN Circular 24191
Subject
LIGO/Virgo S190425z: Candidates from the Zwicky Transient Facility
Date
2019-04-25T17:46:37Z (6 years ago)
From
Mansi M. Kasliwal at Caltech/Carnegie <mansikasliwal@gmail.com>
Mansi M. Kasliwal (Caltech), Michael W. Coughlin (Caltech), Eric C. Bellm
(UW), Leo P. Singer (NASA GSFC), K. De (Caltech), Igor Andreoni (Caltech),
Dmitry Duev (Caltech), Shreya Anand (Caltech), Tomas Ahumada (UMD), S.
Bradley Cenko (NASA GSFC), D. Goldstein (Caltech), A. Ho (Caltech), D. A.
Perley (LJMU), V. Bhalerao (IITB), H. Kumar (IITB), Y. Sharma (IITB), C.
Copperwheat (LJMU), Virginia Cunningham (UMD), Shaon Ghosh (UWM), Ariel
Goobar (OKC), David Kaplan (UWM), Jesper Sollerman (OKC), Joshua S. Bloom
(UCB), M. Bulla (OKC), Nobuyuki Kawai (Tokyo Tech), Yoichi Yatsu (Tokyo
Tech), Katsuhiro Murata (Tokyo Tech), Hidekazu Hanayama (IAO), Takashi
Horiuchi (IAO), G. C. Anupama (IIA), M. Rigault (CNRS/IN2P3), C.
Barbarino(OKC), R. Biswas (OKC), D. Cook (Caltech), G. Helou (IPAC)
On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of
Observatories Watching Transients Happen (GROWTH) collaborations
We observed the localization region of the gravitational wave trigger
S190425z (GCN 24168) with the Palomar 48-inch telescope equipped with the
47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019). We
were already observing the GW localization region as part of routine survey
operations. A new tiling was automatically optimally determined and
triggered using the GROWTH Target of Opportunity marshal (Coughlin et al.
2019a, Kasliwal et al. 2019b). We started obtaining target-of-opportunity
observations in the g-band and r-band filters beginning at UT 2019-04-25
09:19:07.161. A total of 4327 square degrees covering 41% of the enclosed
probability were observed before 12-deg twilight and analyzed in real-time.
Each exposure was 30s with a typical depth of 20.4 mag.
The images were processed through the ZTF reduction and image subtraction
pipelines at IPAC to search for potential counterparts (Masci et al. 2019).
After rejecting stellar sources (Tachibana and Miller 2018) and moving
objects and applying machine learning algorithms (Mahabal et al. 2019),
several high-significance transient candidates were identified by our
pipeline in the area observed.
Our most promising candidates thus far are:
------------------------------------------------------------------------
ZTF Name | RA (deg) | DEC (deg) | Filter | Mag | Magerr
--------------+-------------+------------+--------+-------+-------------
ZTF19aarykkb | 258.341454 | -9.964466 | r | 18.63 | 0.10
ZTF19aarzaod | 262.791487 | -8.450722 | r | 20.11 | 0.18
--------------+-------------+------------+--------+-------+-------------
ZTF19aarykkb is near 2MASX J17132113-0957536 at z=0.024. ZTF19aarzaod is
near 2MASX J17311017-0827103 at z=0.028. Both have no ZTF detections prior
to the reported binary neutron star merger time (although our most recent
upper limits are only from 2019 April 19). Both host galaxies are in the
Census of the Local Universe (CLU) galaxy catalog (Cook et al. 2017). Thus,
with the data in-hand, the position, redshift of putative host galaxy ,
age, color and luminosity of both events are consistent with the GW
trigger. The positions are also consistent with being in the region that
Fermi-GBM could not constrain (GCN 24185). Both candidates have not yet
been reported to the Transient Name Server. We caution that we cannot rule
out these are young supernovae and spectroscopic follow-up is urgently
needed. Additional analysis and follow-up is ongoing.
Also, just as a reference, we also provide a list of relatively young
candidates whose first ZTF detection was within the past three days below,
including a magnitude measurement from tonight. We emphasize that all the
events listed below have recent previous detections with ZTF prior to the
gravitational wave event trigger time and are unlikely to be related to
S190425z (e.g., background supernovae, active galactic nuclei, foreground
CV).
------------------------------------------------------------------------
ZTF Name | RA (deg) | DEC (deg) | Filter | Mag | Magerr
--------------+-------------+------------+--------+-------+-------------
ZTF19aarzfoz | 235.600249 | 19.5876421 | g | 19.90 | 0.21
ZTF19aarpptk | 254.2036677 | 9.6049366 | g | 18.10 | 0.05
ZTF19aarywve | 250.9039956 | 17.5801296 | r | 20.45 | 0.19
ZTF19aarpfjs | 252.0464742 | 1.0668639 | r | 18.93 | 0.10
ZTF19aarkmsl | 242.401716 | 25.7497917 | r | 19.40 | 0.18
ZTF19aarppnl | 258.9096792 | 15.7457655 | g | 19.80 | 0.11
ZTF19aarpplo | 262.9779752 | 18.7380718 | g | 19.74 | 0.17
ZTF19aarypbv | 248.5874816 | 30.5050049 | g | 20.48 | 0.29
ZTF19aartzok | 238.9634555 | 36.3591878 | g | 20.27 | 0.20
ZTF19aarxvub | 265.2782205 | 8.470448 | r | 19.53 | 0.13
ZTF19aaryvld | 250.075357 | 9.1071601 | r | 20.01 | 0.18
ZTF19aarpzuh | 252.1452493 | 15.7402238 | r | 20.19 | 0.16
ZTF19aarprog | 248.5427404 | 19.6347848 | r | 19.00 | 0.11
ZTF19aarycpi | 245.0910206 | 18.348845 | r | 19.20 | 0.10
ZTF19aailtzw | 256.934132 | 2.948056 | r | 18.50 | 0.08
------------------------------------------------------------------------
ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC,
USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY,
Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan;
IIT-B, India; IIA, India; LJMU, UK and USyd, Australia. ZTF acknowledges
the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH
acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert
distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert
filtering and follow-up co-ordination is being undertaken by the GROWTH
marshal system (Kasliwal et al. 2019).
GCN Circular 24192
Subject
LIGO/Virgo S190425z: J-GEM optical follow-up observations with Subaru/FOCAS
Date
2019-04-25T17:56:25Z (6 years ago)
From
Mahito Sasada at Hiroshima University <sasadam@hiroshima-u.ac.jp>
Sasada, M., Akitaya, H., Nakaoka, T. (Hiroshima U.), Yoshida, M. (NAOJ/Subaru),
Tanaka, M. (Tohoku U.), Tominaga N., Ohgami, T., Kaneko A. (Konan U.),
Itoh, R. (Bisei Astronomical Observatory), Sekiguchi, Y. (Toho U.),
Utsumi, Y. (Stanford U./SLAC), Morokuma, T., Niino, Y., Ohsawa, R. (U.
of Tokyo),
Murata, K. L. (Tokyo Tech), on behalf of J-GEM collaboration
We report our optical imaging observations of galaxies in the
localization region of the BNS gravitational wave event S190425z (The
LIGO Scientific Collaboration and the Virgo Collaboration, 2019, GCN,
24168) using the Faint Object Camera and Spectrograph (FOCAS; 6 arcmin
field-of-view in diameter; Kashikawa et al. 2002, PASJ, 54, 819) on
the 8.2-m Subaru telescope. We started our observations at UT
2019-04-25 11:46, about 3.5 hours after the event.
We observed 154 galaxies in total. The target galaxies are selected
from the list of potential host galaxies for this event (Dalya et al.
2019, GCN, 24171) around the central coordinate of the localization of
the gamma-ray pulses detected with INTEGRAL/SPI-ACS (Minaev et al.
2019, GCN, 24170). The list of the galaxies we observed is shown in
the table below.
We took ten-second r-band images for each galaxy with typical 5-sigma
depths of 23-24 mag. The obtained images are compared with the
Pan-STARRS r-band images (Chambers et al., 2016, arXiv:1612.05560)
with similar or slightly shallower depths compared to our FOCAS
images. In these galaxies, we find no apparent transient objects that
are not registered in the IAU Transient Name Server
(https://wis-tns.weizmann.ac.il).
Galaxy name RA Dec
2MASS16522624+2319575 16:52:26.24 +23:19:57.5
NGC6051 16:04:56.70 +23:55:58.3
NGC6062 16:06:22.80 +19:46:40.6
60191 17:23:26.11 +23:38:39.5
NGC6308 17:11:59.72 +23:22:48.3
57296 16:09:15.67 +25:42:45.0
56144 15:49:57.32 +20:48:18.6
UGC10138 16:01:40.23 +21:21:10.6
UGC10153 16:03:19.52 +20:38:12.5
57607 16:14:57.83 +21:56:17.9
58028 16:24:15.15 +20:11:00.9
56443 15:56:33.64 +20:03:08.2
56713 16:01:28.67 +22:25:39.6
NGC6203 16:40:27.38 +23:46:29.1
57072 16:05:29.16 +19:56:31.7
2MASS16313806+2047366 16:31:38.06 +20:47:36.6
58396 16:30:47.15 +20:21:19.3
NGC6233 16:50:15.72 +23:34:47.4
1683153 16:32:58.94 +23:11:51.0
1745822 16:09:51.84 +25:41:11.6
59087 16:50:14.26 +23:26:28.4
58322 16:29:17.35 +20:21:53.3
58537 16:34:53.70 +23:12:42.2
UGC10224 16:08:50.23 +22:02:33.4
2MASS18405128+2334077 18:40:51.28 +23:34:07.7
58006 16:23:40.08 +24:28:26.6
1695642 16:22:57.30 +23:53:35.9
1631905 16:16:11.90 +20:36:45.1
UGC10834 17:24:32.84 +20:23:53.0
1612380 16:00:30.52 +19:59:07.0
55776 15:40:37.22 +20:33:44.7
56150 15:49:59.28 +20:48:20.6
UGC10260 16:11:57.87 +20:55:24.4
NGC6075 16:11:22.56 +23:57:54.5
57272 16:08:33.84 +21:04:52.3
1635109 15:44:24.00 +20:45:09.5
214459 16:06:00.72 +20:50:50.2
2MASS16060593+2047032 16:06:05.93 +20:47:03.2
2MASS16072060+2058306 16:07:20.60 +20:58:30.6
3089913 16:06:16.28 +21:03:49.2
PGC1626696 12:03:48.25 +20:24:58.9
56856 16:03:17.78 +21:35:30.5
56706 16:01:25.27 +21:55:57.5
1661347 16:04:50.77 +21:59:23.3
214390 15:35:04.81 +23:28:45.7
56084 15:48:33.88 +22:58:20.8
57085 16:05:36.81 +22:11:10.8
56652 16:00:38.21 +22:32:37.0
57526 16:13:25.54 +21:54:33.8
SDSSJ153858.32+234650.8 15:38:58.33 +23:46:50.8
2MASS16073961+2220315 16:07:39.61 +22:20:31.5
1671243 16:05:23.40 +22:30:27.6
IC4573 15:42:12.27 +23:48:00.5
57116 16:05:58.62 +22:37:55.9
57420 16:11:20.97 +22:22:31.3
56853 16:03:13.71 +23:00:29.5
UGC10236 16:10:05.09 +22:39:01.1
56252 15:52:02.13 +23:44:02.7
UGC10066 15:51:36.87 +23:47:24.1
1688132 16:03:44.45 +23:28:55.4
57542 16:13:46.01 +22:55:07.9
57472 16:12:20.33 +23:00:07.0
56175 15:50:38.65 +20:22:54.7
1623900 16:04:43.49 +20:19:25.3
56534 15:58:33.94 +20:11:06.3
UGC10060 15:51:06.90 +20:12:09.2
3089914 16:18:24.75 +20:53:23.9
1686786 15:10:28.49 +23:24:14.4
PGC1689724 15:11:16.57 +23:34:20.9
2MASS16182990+2209489 16:18:29.90 +22:09:48.9
1684230 15:50:20.24 +23:15:32.7
1690340 15:43:51.42 +23:36:26.5
1668320 16:19:07.19 +22:21:07.7
55690 15:38:59.04 +23:46:54.0
1672257 16:17:11.69 +22:33:46.9
57493 16:12:42.77 +22:59:02.7
2MASS16141210+2307136 16:14:12.10 +23:07:13.6
57263 16:08:23.52 +23:28:24.7
57265 16:08:22.57 +23:28:46.7
56963 16:04:36.61 +23:39:47.3
1691288 16:04:59.95 +23:39:30.4
57021 16:05:02.50 +23:40:08.5
56958 16:04:33.46 +23:50:16.3
57003 16:04:50.57 +23:58:30.3
57014 16:04:59.47 +23:58:12.3
56887 16:03:41.89 +24:05:42.5
1692398 16:12:07.70 +23:43:04.9
UGC10256 16:11:30.77 +23:48:42.3
56991 16:04:46.81 +24:16:43.2
1694999 16:12:14.17 +23:51:28.9
57105 16:05:49.61 +24:10:32.8
1705857 16:03:14.25 +24:22:23.2
57406 16:11:14.38 +24:13:29.5
1717114 16:04:16.27 +24:48:44.4
UGC10160 16:03:54.24 +25:00:38.0
57029 16:05:11.46 +24:57:36.7
56949 16:04:35.57 +25:11:23.3
57293 16:09:06.46 +24:52:13.0
1686035 16:36:40.62 +23:21:36.5
58712 16:39:41.29 +23:30:53.4
58345 16:29:44.04 +23:21:10.6
UGC10320 16:18:07.32 +21:03:58.9
58744 16:40:50.93 +23:39:34.0
58371 16:30:13.32 +23:04:11.1
58050 16:24:45.01 +23:57:54.3
58363 16:30:02.71 +23:21:16.1
56249 15:52:05.66 +20:08:42.7
58360 16:29:53.36 +20:13:57.6
60508 17:34:06.29 +23:31:09.2
1642211 16:21:09.60 +21:04:30.3
56874 16:03:28.01 +20:17:32.3
PGC058850 16:43:36.19 +20:13:53.8
1621936 16:47:43.70 +20:15:48.6
56961 16:04:35.71 +25:43:14.3
57893 16:21:04.24 +21:20:26.3
NGC6201 16:40:14.41 +23:45:55.0
58042 16:24:34.15 +21:11:41.3
2MASS15503893+2023227 15:50:38.93 +20:23:22.7
1736488 16:10:48.42 +25:26:12.6
60430 17:31:15.29 +23:35:01.8
1614726 15:57:32.18 +20:03:12.8
57765 16:18:05.32 +21:33:12.9
NGC6062B 16:06:18.93 +19:45:47.2
58415 16:31:06.58 +23:49:57.7
1673429 16:20:44.20 +22:38:00.7
2MASS16345531+2034432 16:34:55.31 +20:34:43.2
2MASS16320391+2045519 16:32:03.91 +20:45:51.9
57752 16:17:49.42 +20:41:28.9
1638586 16:27:04.49 +20:54:35.2
1685163 16:33:32.29 +23:18:43.4
57391 16:10:52.39 +22:37:32.2
1603948 16:13:55.38 +19:44:45.9
56282 15:52:43.13 +20:13:59.8
1692904 16:52:11.03 +23:44:39.6
UGC10525 16:44:04.21 +23:23:52.1
60413 17:30:34.99 +23:37:28.9
57290 16:09:07.26 +21:52:03.7
59153 16:52:17.31 +23:18:01.5
2MASS16302400+2026011 16:30:24.00 +20:26:01.1
1667049 16:02:25.59 +22:17:02.5
59213 16:53:53.83 +20:35:51.8
1628794 16:25:52.24 +20:29:19.8
57283 16:08:58.14 +19:49:25.5
1657664 16:19:02.35 +21:48:22.7
1632425 16:25:00.27 +20:38:04.5
1612760 15:57:33.04 +19:59:43.8
1688390 16:29:48.38 +23:29:45.6
1664646 16:05:13.92 +22:09:32.6
1610658 16:05:32.29 +19:56:04.8
1727092 16:11:38.16 +25:09:11.6
1736885 16:03:52.36 +25:26:48.6
2MASS16282647+2341107 16:28:26.47 +23:41:10.7
3089915 16:20:34.24 +21:12:08.7
1699245 16:11:35.70 +24:04:35.6
GCN Circular 24193
Subject
LIGO/Virgo S190425z: Lulin Follow-Up Observations
Date
2019-04-25T19:55:03Z (6 years ago)
From
Mansi M. Kasliwal at Caltech/Carnegie <mansikasliwal@gmail.com>
Han-Jie Tan (NCU), Po-Chieh Yu (NCU), Chow-Choong Ngeow (NCU), Wing-Huen Ip
(NCU)
On behalf of Global Relay of Observatories Watching Transients Happen
(GROWTH) collaborations
We report the photometric measurements of two promising candidates
ZTF19aarykkb and ZTF19aarzaod (GCN 24191) associated with the gravitational
wave trigger S190425z (GCN 24168) using Lulin One-meter Telescope(LOT) in
Taiwan. The observations were conducted using g, r, i filters at 2019-04-25
15:57:19 UT, ~7.65 hours after the trigger, and 2019-04-25 17:25:43, ~9.12
hours after the trigger, respectively. Preliminary photometry were obtained
by calibrating with Pan-STARRS catalog.
We would like to thank the staff in Lulin Observatory for helping the
observations.
Summary of ZTF19aarykkb:
UT Filter Exp(s)
Mag (AB)
2019-04-25 15:58:49 g 180 18.84+/-0.04
2019-04-25 16:02:11 r 180 18.23+/-0.02
2019-04-25 16:05:33 i 180 17.92+/-0.02
Summary of ZTF19aarzaod:
2019-04-25 17:48:24 g 300 21.45+/0.47
2019-04-25 17:53:45 r 300
20.26+/-0.25
2019-04-25 17:41:56 i 300
19.93+/-0.13
Also, we searched for optical counterpart in 90% localization area of
LIGO/Virgo S190425z (GCN 24168). The observation started at 2019-04-25
12:27:23 UT, 249 minutes after the trigger, and 27 galaxies were observed
in R-band with 180 second exposure time. No obvious transient can be
identified brighter than R~20 mag (AB). The galaxy coordinates are listed
below.
RA(deg) DEC(deg)
194.9152 +53.341
212.0897 +55.302
212.6985 +35.913
213.2136 +35.711
213.6132 +36.404
216.0865 +36.461
217.9843 +33.643
218.3270 +34.735
219.1718 +34.973
232.4191 +30.486
235.3749 +27.986
236.0957 +25.327
236.3709 +26.603
236.9752 +25.729
239.0161 +24.448
239.2193 +24.662
239.2199 +25.569
239.6450 +27.618
239.7168 +26.136
239.9651 +25.941
241.1394 +23.838
241.2978 +24.960
242.2803 +21.868
242.7183 +22.626
242.8088 +26.923
242.8782 +23.812
243.0847 +23.002
GCN Circular 24194
Subject
LIGO/Virgo S190425z: ZTF19aarzaod Imaging from Las Cumbres Observatory
Date
2019-04-25T20:40:43Z (6 years ago)
From
Daichi Hiramatsu at Las Cumbres Observatory <dhiramatsu@lco.global>
Daichi Hiramatsu (LCO/UCSB), Iair Arcavi (Tel Aviv University), Jamison
Burke (LCO/UCSB), D. Andrew Howell (LCO/UCSB), Curtis McCully (LCO), Craig
Pellegrino (LCO/UCSB) on behalf of the Las Cumbres GW Follow-up
Collaboration
On 2019-04-25 19:21:09 UT we obtained two g-band images of the GW optical
counterpart candidate ZTF19aarzaod (Kasliwal et al. 2019, GCN 24191) with
the Las Cumbres Observatory 1m telescope at the Siding Spring Observatory
in Australia. We detect the candidate with a magnitude of g = 21.3��0.14
(using PSF fitting), consistent with the Tan et al. (2019, GCN 24193)
measurement.
GCN Circular 24195
Subject
LIGO/Virgo S190425z: CLU/NED Galaxies in the Localization Volume
Date
2019-04-25T21:13:20Z (6 years ago)
From
David Cook at IPAC/Caltech <dcook@ipac.caltech.edu>
LIGO/Virgo S190425z: CLU/NED Galaxies in the Localization Volume
David O. Cook (Caltech/IPAC), Angela Van Sistine (UW Milwaukee), Leo Singer (NASA/GSFC), Igor Andreoni (Caltech), Michael Coughlin (Caltech), Bob Aloisi (UW Milwaukee), Patrick R. Brady (UW Milwaukee), Rick Ebert (Caltech/IPAC), George Helou (Caltech/IPAC), David Kaplan (UW Milwaukee), Mansi M. Kasliwal (Caltech), Joseph M. Mazzarella (Caltech/IPAC), and Marion Schmitz (Caltech/IPAC)
On behalf of the Global Relay of Observatories Watching Transients Happen (GROWTH) collaboration and the NASA/IPAC Extragalactic Database (NED) Team.
We spatially cross-matched the LIGO/Virgo S190425z trigger sky localization (90% containment volume) with the Census of the Local Universe (CLU; Cook et al. 2017; arxiv:1710.05016) galaxy catalog and found 69288 galaxies within the volume. The CLU catalog is a compilation of galaxies with existing redshifts from many sources (e.g., NED, SDSS, etc) and new galaxies from a 3PI steradian narrow-band survey to look for redshifted Halpha emission out to 200 Mpc with the Palomar Oschin 48-inch telescope (Cook et al. 2017; arxiv:1710.05016). We list here the top 20 CLU-matched galaxies sorted by stellar mass (Mstar) whose location on the sky and distance falls in the 90% volume reported by the BAYESTAR probability sky map (Singer et al. 2016). We also list the dust-corrected star formation rates (SFRs) for galaxies with GALEX FUV detections (a 'nan' for those with no detection).
For a more extended list of galaxies in the 90% volume go to the NED Gravitational Wave Followup service at https://ned.ipac.caltech.edu/uri/NED::GWF/. This service provides downloadable galaxy lists and visualizations for candidate host galaxies. For each GW alert, these products are automatically generated and made available within minutes to expedite efficient electromagnetic followup observations. The NED top 20 list is sorted by 2MASS absolute K-band magnitude, but users can sort the entire list on a variety of other criteria (probability density, UV magnitudes, etc) after download.
name ra dec distmpc logsfr_fuv logmstar dP_dV
------------------------ -------- ------- ------- ---------- -------- --------
HIZOA J1822-21 275.5775 -21.1603 105.49 nan 12.52 3.12e-07
2MASXi J0215532-232855 33.9721 -23.4821 155.60 nan 12.15 1.12e-07
2MASX J06090714+2150343 92.2798 21.8428 92.75 nan 12.14 2.89e-07
2MASX J05210136-2521450 80.2558 -25.3626 177.23 2.36 12.03 5.47e-08
FAIRALL 0009 20.9407 -58.8058 195.77 1.83 11.95 3.91e-08
HIZOA J1749-32A 267.2717 -32.4039 117.43 nan 11.95 7.06e-08
LDCE 1285 271.5879 -25.4325 104.81 nan 11.92 1.69e-07
IRAS 05223+1908 81.3187 19.1794 123.16 nan 11.87 1.75e-07
ESO 250-G 012 63.2014 -46.6193 136.77 0.72 11.85 9.70e-08
ARK 120 79.0476 -0.1498 138.25 nan 11.83 1.26e-07
2MASX J04444356-4433487 71.1814 -44.5635 195.96 nan 11.80 3.74e-08
HIZOA J1752-32 268.0325 -32.6194 82.71 nan 11.72 5.58e-08
2MASS J17421439-0843195 265.5582 -8.7228 95.94 nan 11.71 2.22e-07
IRAS 05589+2828 90.5446 28.4728 137.41 nan 11.66 5.27e-08
NGC 5995 237.1040 -13.7578 104.91 1.42 11.61 6.35e-08
3C 120 68.2962 5.3543 137.45 nan 11.56 6.87e-08
2MASS J04145265-0755396 63.7195 -7.9277 158.89 1.53 11.55 5.89e-08
MRK 0618 69.0927 -10.3761 148.03 1.66 11.52 8.09e-08
CGCG 049-037 227.9241 4.4919 155.60 -0.73 11.51 9.24e-08
HIZOA J1749-32B 267.4346 -32.5875 80.95 nan 11.51 5.46e-08
Table: Top 20 galaxies in CLU that fall in the 90% probability volume for S190425z sorted by stellar mass. Column descriptions are as follows. name: galaxy name. ra: RA (J2000, decimal degrees). dec: Dec (J2000, decimal degrees). distmpc: galaxy distance (Mpc). logsfr_fuv: log10 of the star formation rate (SFR, Msun per year), derived from GALEX All Sky Kron FUV magnitudes via the prescription of Murphy et al. (2011), corrected for internal dust extinction using a combination of GALEX FUV and 22um ALLWISE fluxes (Hao et al. 2011). logmstar: log10 of the galaxy stellar mass (Msun), estimated from 3.4um ALLWISE fluxes and a mass-to-light ratio of 0.5 (McGaugh & Schombert et al. 2015).
GCN Circular 24196
Subject
LIGO/Virgo S190425z: OVRO-LWA simultaneous low frequency radio observations of localization region
Date
2019-04-25T21:21:41Z (6 years ago)
From
Marin M Anderson at Caltech <mmanders@astro.caltech.edu>
M. M. Anderson (Caltech), T. A. Callister (Caltech), G. Hallinan (Caltech) on behalf of the OVRO-LWA collaboration.
We report contemporaneous observations of the localization region of the BNS gravitational wave event S190425z (GCN 24168) with the OVRO-LWA. The observations span from -1 hour to +3 hour relative to the merger time (2019-04-25 08:18:05.17 UT), with continuous coverage of approximately 57% of the probability region. This includes the locations of the 2 candidates identified in ZTF (GCN 24191). The OVRO-LWA is a low-frequency radio telescope operating from 28 MHz to 86 MHz, with an approximately 20,000 sq. deg. instantaneous field-of-view.
Data reduction and analysis have commenced investigating the possible presence of a low frequency prompt counterpart to the event (see Anderson et al. 2018, Callister et al. 2019).
GCN Circular 24197
Subject
LIGO/Virgo S190425z: ATLAS observations of the S190425z skymap
Date
2019-04-25T21:45:52Z (6 years ago)
From
Stephen Smartt at Queen's U/Belfast <s.smartt@qub.ac.uk>
O. McBrien, S. Smartt, K. W. Smith, D. R. Young, (Queen's University
Belfast), L. Denneau, H. Flewelling, A. Heinze, J. Tonry, H. Weiland,
(IfA, Univ. of Hawaii), J. Gillanders, S. Srivastav, D. O'Neil, P.
Clark, S. Sim (QUB), A. Rest (STScI), B. Stalder (LSST), C. Stubbs
(Harvard), E. Magnier, A. Schultz, , M. Huber, K. C. Chambers (IfA)
We report observations of the BAYESTAR skymap of the BNS event
S190425z (The LIGO Scientific Collaboration and the Virgo
Collaboration, GCN 24168) with the ATLAS telescope system (Tonry et
al. 2018, PASP, 13, 164505). ATLAS is a twin 0.5m telescope system on
Haleakala and Mauna Loa employing two filters cyan and orange. While
carrying out the primary mission for Near Earth Objects, we can adjust
the schedule rapidly to point at LVC gravitational wave skymaps.
Sequences of 30 sec images were taken in the ATLAS o bands, and at
each pointing position a sequence of quads (4 x 30 sec) was taken. The
images were processed with the ATLAS pipeline and reference images
subtracted from each one. Transient candidates were run through our
standard filtering procedures, combined with machine learning
algorithms (e.g. Wright et al. 2015, MNRAS, 449, 451). Candidates were
spatially cross-matched with known minor planets, and star, galaxy,
AGN and multi-wavelength catalogues (as described in Smartt et al.
2016, MNRAS, 462 4094, Stalder et al. 2017, ApJ, 850, 149).
We began observing the northern part of the skymap within the first
hour of the preliminary notice. ATLAS covered 2652 squ. degrees of the
bayestar map 90% credible region and covered a sky region totalling of
37.2% of the event's localisation likelihood. A single image reaches
approximately o = 19.5 (5 sigma),
We flagged 25 transients but all were either known, or we detected
previous flux in our own forced photometry in images before the explosion.
These new objects were registered on the TNS. Users are referred there as
a reference point.
No further convincing counterpart candidates were found above o =
19.5, which were plausibly associated with a galaxy within 100-200 Mpc
(i.e. less than 50 kpc separation). Our area did not cover the sky position of the two
ZTF candidates (see Kasliwal et al. GCN 24191).
In addition we report 5 marginal candidates. These are all orphans (not
matched with any known source), but require independent confirmation.
They are within the skymap (at least 30% contour).
Name | IAU Name | RA (J2000) | Dec (J2000) | Disc. MJD | Disc Mag
ATLAS19hxm | AT2019dzv |14:01:45.02 | +46:12:56.1 | 58598.42 | 19.23 o
ATLAS19hyx | AT2019ebl |14:32:31.53 | +55:45:00.1 | 58598.44 | 19.28 o
ATLAS19hyo | AT2019eao |13:01:18.63 | +52:09:02.1 | 58542.59 | 19.36 o
ATLAS19hwn | AT2019ebm |12:59:58.58 | +29:14:30.7 | 58598.40 | 19.42 o
ATLAS19hwh | AT2019ebn |13:54:47.42 | +44:46:27.3 | 58318.29 | 19.07 o
This work has made use of data from the Asteroid Terrestrial-impact
Last Alert System (ATLAS) project. ATLAS is primarily funded to search
for near earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284,
and 80NSSC18K1575; byproducts of the NEO search include images and
catalogs from the survey area. The ATLAS science products have been
made possible through the contributions of the University of Hawaii
Institute for Astronomy, the Queen's University Belfast, and the
Space Telescope Science Institute.
GCN Circular 24198
Subject
LIGO/Virgo S190425z: KPED Follow-Up Observations
Date
2019-04-25T21:54:41Z (6 years ago)
From
Tomas Ahumada at U. of Maryland <tahumada@astro.umd.edu>
Authors: Tomas Ahumada (UMD), Michael W. Coughlin (Caltech), Kai Staats
(Embry-Riddle University), Richard G. Dekany
<https://arxiv.org/search/astro-ph?searchtype=author&query=Dekany%2C+R+G>
(Caltech), Dmitry A. Duev
<https://arxiv.org/search/astro-ph?searchtype=author&query=Duev%2C+D+A>
(Caltech), Michael Feeney
<https://arxiv.org/search/astro-ph?searchtype=author&query=Feeney%2C+M>
(Caltech), S. R. Kulkarni
<https://arxiv.org/search/astro-ph?searchtype=author&query=Kulkarni%2C+S+R>
(Caltech), Reed Riddle
<https://arxiv.org/search/astro-ph?searchtype=author&query=Riddle%2C+R>
(Caltech) on behalf of the KPED team and the Global Relay of Observatories
Watching Transients Happen (GROWTH) collaboration.
We used the Kitt Peak EMCCD Demonstrator (KPED) on the Kitt Peak 84-inch
telescope (Coughlin et al 2019b) to obtain 300 s r-band images for 10
galaxies in the 90% localization region of the S190425z LIGO/Virgo
detection (GCN 24168). The observations started 10:12 UT on 2019 April 25
(about ~1.9 hours after the event) and the median 5 sigma upper limit for
an isolated point source in our images was r > 20.8. No transients were
detected in any of the galaxies listed below:
Name | R.A. | Dec.
------------------------------------------------------------------------
NGC6166 | 16:28:38.23 | 39:33:04.4
NGC4889 | 13:00:08.13 | 27:58:37.2
CB-11.4459 15:18:32.09 | 31:09:40.82
1200-07486009 | 15:12:12.73 | 31:54:36.17
J15122693+3224040
<http://simbad.u-strasbg.fr/simbad/sim-id?Ident=%4012318336&Name=2MASX%20J15122693%2b3224040&submit=submit>
| 15:12:26.92 | 32:24:03.84
J151717.32+304801.3 | 15:17:17.33 | 30:48:01.33
J151303.42+325505.8 | 15:13:03.43 | 32:55:05.81
J15120209+3254551
<http://simbad.u-strasbg.fr/simbad/sim-id?Ident=%402909607&Name=2MASX%20J15120209%2b3254551&submit=submit>
| 15:12:02.07 | 32:54:55.29
J15113637+3142477
<http://simbad.u-strasbg.fr/simbad/sim-id?Ident=%4011050786&Name=2MASX%20J15113637%2b3142477&submit=submit>
| 15:11:36.34 | 31:42:47.31
J151109.81+313833.2 | 15:11:09.82 | 31:38:33.2
The KPED team thanks the National Science Foundation, the National Optical
Astronomical Observatory and the Murty family for support in the building
and operation of KPED.
GCN Circular 24199
Subject
LIGO/Virgo S190425z: STARE2 simultaneous L-band radio observations
Date
2019-04-25T22:23:37Z (6 years ago)
From
Christopher Bochenek at California Institute of Technology <cbochenek@astro.caltech.edu>
C. D. Bochenek (Caltech), S. R. Kulkarni (Caltech), D. McKenna (Caltech), K. Belov (JPL), V. Ravi (Harvard, Caltech)
STARE2 is an all-sky instrument located at the Owens Valley Radio Observatory (OVRO) and the Goldstone Deep Space Communications Complex designed to search for fast radio transients. STARE2 is sensitive to millisecond duration bursts of radio emission above 157 kJy, for a burst at zenith. The beam pattern of the instrument is attached. STARE2 regularly sees type IIIdm bursts from the Sun.
No candidate events were found within 3 hours of the event.
Observing frequency: 1280-1530 MHz
Time resolution: 65.536 microseconds
Maximum timescale STARE2 is sensitive to: 34 ms
Frequency resolution: 122.07 kHz
Dispersion measure search range: 5 pc cm^-3 - 3000 pc cm^-3
If the event happened at the location of ZTF19aarykkb (GCN 24191) and a millisecond duration burst, we limit the flux to < 1.5 MJy.
The sky at OVRO at the time of the event contains 57% of the LIGO localization region (GCN 24196).
GCN Circular 24200
Subject
LIGO/Virgo S190425z - HCT spectroscopy
Date
2019-04-26T00:12:52Z (6 years ago)
From
Varun Bhalerao at Indian Inst of Tech <varunb@iitb.ac.in>
Pavana M., G. C. Anupama, B. S. Kiran (IIA) and V. Bhalerao (IITB) report on behalf of a larger collaboration:
We observed the potential counterpart ZTF19aarykkb (Kasliwal et al., GCN 24191) to the GW candidate S190525z (GCN 24168) with the HFOSC instrument on the 2m Himalayan Chandra Telescope. We obtained 2x30min exposures in the g7 grism and 1x30min exposure in the g8 grism. Spectra were reduced following standard techniques in IRAF.
The spectra show a broad, relatively featureless, continuum. We see emission features corresponding to H alpha and He II (4686) at the host redshift of 0.024. At this time, host contamination cannot be ruled out. The He II feature, if confirmed, indicates a very hot source. Further spectroscopic follow-up observations are encouraged.
GCN Circular 24201
Subject
LIGO/Virgo S190425z - GROWTH-India follow-up of two ZTF candidates
Date
2019-04-26T00:20:56Z (6 years ago)
From
Varun Bhalerao at Indian Inst of Tech <varunb@iitb.ac.in>
V. Bhalerao, H. Kumar, V. Karambelkar, G. Waratkar, Y. Sharma (IITB), G. C. Anupama (IIA) report on behalf of the GROWTH collaboration:
We observed the two most promising candidates reported by the Zwicky Transient Facility (Kasliwal et al., GCN 24191) for the follow up the GW candidate S190425z (GCN 24168) with the GROWTH-India telescope. We obtained multiple images in g, r, and i bands, with exposures ranging from 300 sec - 600 sec. Source photometry for ZTF19aarykkb is given below.
Date-Time MJD exptime Filter Magnitude Magerr
2019-04-25 18:25:39 2458599.268 600 r 17.78 0.06
2019-04-25 18:06:40 2458599.255 600 r 17.82 0.08
2019-04-25 21:54:37 2458599.413 300 g 18.49 0.05
2019-04-25 22:01:34 2458599.418 300 g 18.46 0.05
2019-04-25 22:08:50 2458599.423 300 r 17.48 0.05
2019-04-25 22:40:29 2458599.445 600 i 16.99 0.04
2019-04-25 22:54:42 2458599.455 600 g 18.62 0.04
2019-04-25 23:06:41 2458599.463 600 g 18.36 0.17
We also observed ZTF19aarzaod multiple times with 3 exposures in g band, 4 r and 2 i band exposures respectively, each with an exposure time of 600 seconds. We see a weak source in the r and i band images, further analysis is underway. The source appears to be fading rapidly in all bands.
The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7 degree field of view, set up by the Indian Institute of Astrophysics and the Indian Institute of Technology Bombay with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA).
GCN Circular 24202
Subject
LIGO/Virgo S190425z: Liverpool Telescope non-detections of ATLAS candidates
Date
2019-04-26T01:08:30Z (6 years ago)
From
Daniel Perley at Liverpool JMU <d.a.perley@ljmu.ac.uk>
D. A. Perley and C. M. Copperwheat (LJMU) report:
We acquired a short sequence (40 seconds each in g/r/i filters) of
imaging at the locations of all five of the marginal ATLAS transients
reported by McBrien et al. (GCN 24197) using IO:O on the 2m Liverpool
Telescope. We do not detect a significant source at the location of
any of these transients. Approximate 3-sigma upper limits (AB,
calculated relative to SDSS or PS1 secondary standards) are:
Name JD magnitude
AT2019eao 2458599.47986 g > 22.1
AT2019eao 2458599.48069 r > 22.1
AT2019eao 2458599.48150 i > 21.2
AT2019ebn 2458599.49142 g > 22.1
AT2019ebn 2458599.49225 r > 22.2
AT2019ebn 2458599.49306 i > 21.8
AT2019ebm 2458599.51188 g > 22.3
AT2019ebm 2458599.51272 r > 22.0
AT2019ebm 2458599.51353 i > 21.7
AT2019ebl 2458599.51785 g > 22.3
AT2019ebl 2458599.51869 r > 22.1
AT2019ebl 2458599.51950 i > 21.8
AT2019dzv 2458599.52163 g > 22.2
AT2019dzv 2458599.52246 r > 21.7
AT2019dzv 2458599.52328 i > 21.7
DisclaimerNone
GCN Circular 24204
Subject
LIGO/Virgo S190425z: Liverpool Telescope spectroscopy of ZTF19aarykkb
Date
2019-04-26T02:17:57Z (6 years ago)
From
Daniel Perley at Liverpool JMU <d.a.perley@ljmu.ac.uk>
D. A. Perley, C. M. Copperwheat, and K. L. Taggart (LJMU) report on
behalf of the GROWTH collaboration:
We obtained two 600-second exposures of ZTF19aarykkb (Kasliwal et al.,
GCN 24191) using the Spectrograph for the Rapid Acquisition of
Transients (SPRAT) on the 2m Liverpool Telescope.
The reduced 1D spectrum shows a broad (full-width ~ 15000 km/s) emission
line centered at 6700 Angstroms, which we associate with broad H-alpha
from the transient. Narrow H-alpha emission at z=0.025 (likely from the
host galaxy) is also detected. We cannot confirm the presence of He II
(tentatively reported by Pavana et al., GCN 24200) or any other
significant features at this time. These observations suggest that this
source is a young Type II supernova, and is unlikely to be associated
with the BNS merger S190425z (GCN 24168).
DisclaimerNone
GCN Circular 24205
Subject
LIGO/Virgo S190425z: SALT spectroscopy of ZTF19aarzaod as a likely type II supernova
Date
2019-04-26T02:47:57Z (6 years ago)
From
Saurabh Jha at Rutgers U <saurabh@physics.rutgers.edu>
D.A.H. Buckley (SAAO), S. W. Jha (Rutgers), J. Cooke (Swinburne), and M.
Mogotsi (SALT/SAAO) report on behalf of the SALT GW collaboration:
We obtained an 1600-sec spectrum of ZTF19aarzaod (=AT 2019dzw; Kasliwal et al.
2019, GCN 24191) with SALT (+RSS) using the PG0300 line grating. The target is
well detected with a red continuum and a broad (~8000 km/s FWHM) H-alpha
emission feature at the redshift of the host galaxy, z=0.028. The data are
consistent with ZTF19aarzaod being a type II supernova, with the red color
likely a result of the heavy Milky Way extinction A_V = 2.2 (Schlafly &
Finkbeiner 2011, ApJ, 737, 103).
GCN Circular 24206
Subject
LIGO/Virgo S190425z: ZTF19aarykkb Imaging from Las Cumbres Observatory
Date
2019-04-26T03:24:29Z (6 years ago)
From
Jamison Burke at Las Cumbres Observatory/UCSB <jburke@lco.global>
Jamison Burke (LCO/UCSB), Daichi Hiramatsu (LCO/UCSB), Iair Arcavi (Tel
Aviv University), D. Andrew Howell (LCO/UCSB), Curtis McCully (LCO), Craig
Pellegrino (LCO/UCSB) on behalf of the Las Cumbres GW Follow-up
Collaboration
Beginning 2019-04-25 21:34:17 we obtained 14 g-, r-, and i-band images of
the GW optical counterpart candidate ZTF19aarykkb (Kasliwal et al. 2019,
GCN 24191) with the Las Cumbres Observatory 1m telescope at the South
African Astronomical Observatory. We present the following PSF photometry
of the target:
Datetime (UT) JD Filter Mag Magerr
2019-04-25 21:34:17 2458599.3987 g 18.79 0.03
2019-04-25 21:38:04 2458599.4013 g 18.79 0.02
2019-04-25 21:42:05 2458599.4041 r 18.18 0.03
2019-04-25 21:44:31 2458599.4058 r 18.18 0.03
2019-04-25 21:47:12 2458599.4076 i 17.95 0.04
2019-04-25 21:49:39 2458599.4093 i 17.96 0.04
2019-04-25 22:15:11 2458599.4271 g 18.80 0.03
2019-04-25 22:20:38 2458599.4309 g 18.82 0.02
2019-04-25 22:26:19 2458599.4348 i 17.93 0.05
2019-04-25 22:31:46 2458599.4386 i 17.97 0.05
2019-04-25 23:25:31 2458599.4759 g 18.97 0.03
2019-04-25 23:29:18 2458599.4785 g 18.95 0.03
2019-04-25 23:33:18 2458599.4813 r 18.12 0.04
2019-04-25 23:35:45 2458599.4830 r 18.14 0.03
These values disagree with the photometry presented in Bhalerao et al. 2019
(GCN 24201) despite the observations being contemporaneous. The g- and
r-band photometry presented here is roughly 0.3 magnitudes fainter, and the
i-band photometry is almost a full magnitude fainter.
GCN Circular 24207
Subject
LIGO/Virgo S190425z: Las Cumbres Observatory Galaxy Targeted Counterpart Search
Date
2019-04-26T03:24:53Z (6 years ago)
From
Daichi Hiramatsu at Las Cumbres Observatory <dhiramatsu@lco.global>
Daichi Hiramatsu (LCO/UCSB), Craig Pellegrino (LCO/UCSB), Jamison Burke
(LCO/UCSB), D. Andrew Howell (LCO/UCSB), Iair Arcavi (Tel Aviv University),
Curtis McCully (LCO) on behalf of the Las Cumbres GW Follow-up Collaboration
We report 300s gri-band images of the following galaxies in the LIGO/Virgo
S190425z localization region (GCN 24168) with the Las Cumbres Observatory
1m and 2m telescopes at Siding Spring, Australia. We find no obvious
candidates after performing image subtraction using SDSS images as
templates. Additional galaxies continue to be observed from our South
African and Chilean sites.
Name RA(J2000) DEC(J200) Time(UT) Filter
Limmag
CSCG136-080 236.975159 +25.729359 2019-04-25 13:16:33 i 21.7
CSCG136-080 236.975159 +25.729359 2019-04-25 13:22:16 r 21.9
CSCG136-080 236.975159 +25.729359 2019-04-25 13:27:58 g 21.0
NGC6240 253.245255 +2.400985 2019-04-25 12:52:57 i 21.4
NGC6240 253.245255 +2.400985 2019-04-25 12:58:42 r 21.8
NGC6240 253.245255 +2.400985 2019-04-25 13:04:26 g 22.0
NGC6051 241.236267 +23.932871 2019-04-25 13:50:21 i 21.5
NGC6051 241.236267 +23.932871 2019-04-25 13:56:06 r 21.9
NGC6051 241.236267 +23.932871 2019-04-25 14:01:51 g 22.1
NGC6086 243.148087 +29.484850 2019-04-25 14:15:41 i 20.0
NGC6086 243.148087 +29.484850 2019-04-25 14:21:24 r 18.8
NGC6086 243.148087 +29.484850 2019-04-25 14:27:06 g 21.3
2MASXJ16542402-0953212 253.600113 -9.889244 2019-04-25 14:55:41 i 18.2
2MASXJ16542402-0953212 253.600113 -9.889244 2019-04-25 15:01:23 r 19.6
2MASXJ16542402-0953212 253.600113 -9.889244 2019-04-25 15:07:04 g 18.2
CGCG137-045 242.276917 +24.870296 2019-04-25 13:35:30 i 22.0
CGCG137-045 242.276917 +24.870296 2019-04-25 13:41:13 r 22.7
CGCG137-045 242.276917 +24.870296 2019-04-25 13:46:56 g 22.6
CGCG137-066 243.740997 +21.938314 2019-04-25 13:30:47 i 20.7
CGCG137-066 243.740997 +21.938314 2019-04-25 13:36:32 r 21.8
CGCG137-066 243.740997 +21.938314 2019-04-25 13:42:17 g 21.7
GCN Circular 24208
Subject
LIGO/Virgo S190425z: GRAWITA TNG observations of ZTF19aarzaod
Date
2019-04-26T03:58:37Z (6 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
L. Izzo (IAA/CSIC), R. Carini (INAF-OAR), S. Benetti (INAF-OAPd), S. Piranomonte (INAF-OAR), P. D'Avanzo, A. Melandri (INAF-OAB), M.T. Botticella (INAF-OAC),
V. D'Elia (ASI-SSDC), V. Testa (INAF-OAR), G. Greco (Urbino Univ.), S. Yang (INAF-OAPd), E. Brocato (INAF-OAAb, INAF-OAR), A. Harutyunyan, C. Padilla Torres (INAF-TNG)
on behalf of GRAWITA report:
We observed ZTF19aarzaod, one of the two most promising counterpart candidates reported by the Zwicky Transient Facility (Kasliwal et al., GCN 24191) for the GW event S190425z (GCN 24168),
with the 3.6m Italian TNG telescope (Canary Islands, Spain), equipped with the DOLORES camera in spectroscopic mode starting on 2019-04-26 at 01:47:38 UT. An optical spectrum, lasting 2700 s,
was obtained using the grism LR-B (wavelength range ~ 400-800 nm).
The spectrum shows a red continuum with a broad emission consistent with being Halpha at the redshift of the host galaxy (z=0.028; Kasliwal et al., GCN 24191). Our results are consistent with the
findings reported by Buckley et al. (GCN 24205) and suggest that ZTF19aarzaod is not related to the GW event S190425z.
We thank the TNG visitor E. Knudstrup.
GCN Circular 24209
Subject
LIGO/Virgo S190425z: ZTF19aarzaod WHT spectroscopy
Date
2019-04-26T04:08:42Z (6 years ago)
From
Andrew Levan at U.of Leicester <a.levan@astro.ru.nl>
K. Wiersema (Warwick), A.J. Levan (Radboud), M. Fraser (UCD), D.T.H. Steeghs (Warwick), P. Jonker (Radboud/SRON), D.B. Malesani (DAWN/NBI and DARK/NBI) and N.R. Tanvir (Leicester) report for a larger collaboration:
"We obtained optical spectroscopy of ZTF19aarzaod (Kasliwal et al. GCN 24191) with the William Herschel Telescope (WHT) + ACAM spectrograph. Observations began at 01:34 UT for a total of 1200s and cover the wavelength range 4000-9000A.
The spectrum shows a broad H-alpha feature at z=0.028 as noted by Buckley et al. (GCN 24205) and Izzo et al. (GCN 24208) which classifies it as an SN II, and indicates it is unlikely to be associated with LIGO/VIRGO S190425z. We note that despite its apparent origin as a core collapse supernova our spectra do not reveal any nebular emission lines close to the transient position that may be expected from the star formation that created the SN progenitor.
We thank the WHT staff, in particular Lillian Dominguez for assistance with these observations ."
GCN Circular 24210
Subject
LIGO/Virgo S190425z: Pan-STARRS observations and transients in the skymap
Date
2019-04-26T05:33:19Z (6 years ago)
From
Ken Smith at Queen's University Belfast <k.w.smith@qub.ac.uk>
K. W. Smith, D. R. Young, O. McBrien, J. Gillanders. S. Srivastav,
S. J. Smartt, D. O'Neil, P. Clark, S. Sim (QUB), K. C. Chambers ,
M. Huber, E. Magnier, A. Schultz, (IfA, Univ. Hawaii), L. Denneau,
H. Flewelling, A. Heinze, J. Tonry, H. Weiland, A. Rest (STScI),
B. Stalder (LSST), C. Stubbs (Harvard)
We report observations of the BAYESTAR skymap of the BNS event S190425z
(The LIGO Scientific Collaboration and the Virgo Collaboration, GCN 24168)
with the Pan-STARRS1 telescope (Chambers et al. 2016, arXiv:1612.05560C).
Images were taken in the PS1 i-band (Tonry et al. 2012, ApJ 750, 99) and at
each pointing position a dithered sequence of 4 x 45 sec was taken. These
dithered sequences were repeated, with overlaps, to map 1258.10 square
degrees of the bayestar map 90% credible region and covered a sky region
totalling of 28.1% of the event's localisation likelihood. We began taking
data at 2019-04-25 09:39:48 (UTC).
The images were processed with the IPP (Magnier et al. 2016, arXiv:1612.05240)
and difference images for the co-added stacks were produced using the
Pan-STARRS1 Science Consortium 3Pi data to detect transient objects. Standard
filtering procedures, combined with a machine learning algorithm (Wright et al.
2015, MNRAS, 449, 451) were applied and all candidates were spatially cross-
matched with known minor planets, and major star, galaxy, AGN and multi-
wavelength catalogues (as described in Smartt et al. 2016, MNRAS, 462 4094).
We report the following transients (bPC denotes the probability contour within
which the transient is found according to the bayestar.fits map).
Name | PS Name | RA (J2000) | Dec (J2000) | z | Disc Mag | bPC | Notes
AT2019ebu | PS19pp | 14 19 49.43 | +33 00 21.7 | | 20.77 i | 30 |
AT2019ebw | PS19pq | 15 02 17.02 | +31 14 51.6 | | 20.92 i | 10 |
AT2019ebv | PS19pr | 15 02 41.20 | +29 12 01.7 | | 20.98 i | 70 |
AT2019eby | PS19ps | 15 10 15.68 | +33 04 17.6 | | 20.22 i | 10 |
AT2019ebz | PS19pv | 15 25 41.74 | +32 19 42.9 | | 20.01 i | 10 |
AT2019ecc | PS19pw | 15 26 29.53 | +31 39 47.5 | | 20.10 i | 10 |
AT2019ecb | PS19px | 15 32 23.52 | +31 04 19.2 | 0.066 | 21.15 i | 10 | (1)
AT2019ece | PS19py | 15 32 54.55 | +33 29 00.8 | 0.083 | 20.33 i | 20 | (2)
AT2019ecg | PS19qa | 15 35 02.10 | +31 08 02.6 | | 21.56 i | 10 |
AT2019ecf | PS19qb | 15 37 22.53 | +31 35 24.5 | | 20.67 i | 10 |
AT2019ech | PS19qd | 15 41 53.81 | +26 59 12.9 | | 20.67 i | 10 |
AT2019eck | PS19qe | 15 44 24.53 | +32 41 11.0 | | 20.81 i | 20 |
AT2019ecj | PS19qf | 15 45 42.22 | +31 32 42.5 | | 20.67 i | 20 |
AT2019ecl | PS19qg | 15 48 11.85 | +29 12 07.1 | | 20.51 i | 10 |
AT2019ebr | PS19qj | 16 35 26.48 | +22 21 36.4 | 0.152 | 19.79 i | 20 | (3)
AT2019ebo | PS19qn | 16 54 54.71 | +04 51 31.5 | | 20.02 i | 10 |
AT2019ebp | PS19qo | 16 59 57.74 | +12 06 18.3 | 0.045 | 20.29 i | 20 | (4)
AT2019ebq | PS19qp | 17 01 18.33 | -07 00 10.4 | | 20.40 i | 10 |
AT2019ebs | PS19qq | 17 09 58.27 | +07 35 44.6 | | 20.81 i | 20 |
AT2019ebt | PS19qr | 17 11 35.79 | +09 48 05.6 | | 20.07 i | 40 |
NOTES
(1) Probable host is 2MASX J15322384+3104169 at 286 Mpc (NED)
(2) Probable host is 2MASS J15325460+3328553 at 365 Mpc (NED)
(3) Coincident with the core of 2MASX J16352643+2221368 at 700 Mpc (NED)
(4) Probable host is 16595787+1206238 at 199 Mpc (GLADE)
GCN Circular 24211
Subject
LIGO/Virgo S190425z - ePESSTO+ NTT observations
Date
2019-04-26T05:38:22Z (6 years ago)
From
Matt Nicholl at Royal Astronomical Soc. <mrn@roe.ac.uk>
M. Nicholl, P. Short (Edinburgh), J. Anderson (ESO), T.-W. Chen (MPE), C. Inserra (Cardiff), O. Yaron (Weizmann), D. R. Young, S. J. Smartt (QUB), C. Angus, M. Pursiainen, P. Wiseman (Southampton), S. Taubenberger (MPA), M. Gromadzki (Warsaw) on behalf of the ePESSTO+ collaboration
We report observations of two possible counterparts to the LIGO/Virgo gravitational wave trigger S190425z (GCN 24168), under the the advanced Public ESO Spectroscopic Survey for Transient Objects (ePESSTO+; see Smartt et al. 2015, A&A, 579, 40 http://www.pessto.org). The observations were performed on the ESO New Technology Telescope at La Silla with the EFOSC2 instrument.
ZTF19aarzaod/AT2019dzw was announced by Kasliwal et al. (GCN 24191) as a promising candidate from a ZTF search of the field. Follow-up spectroscopy by Buckley et al. (GCN 24205), Izzo et al. (GCN 24208) and Wiersema et al. (GCN 24209) indicated the transient is a young Type II supernova. Our NTT spectrum shows a broad feature consistent with H-alpha at the redshift of the host galaxy (z=0.028).
ATLAS19hwn/AT2019ebm was announced by McBrien et al. (GCN 24197) as a marginal candidate identified during targeted imaging of the localisation region by ATLAS. Follow up observations by Perley et al. (GCN 24202) did not recover the reported source to a limit of r>22.0 mag. We obtained deep imaging to look for a rapidly fading transient. A 5x200s observation in r band shows no source at this position, with preliminary analysis indicating a limit of r>23 mag.
GCN Circular 24212
Subject
LIGO/Virgo S190425z: Swope follow-up observations
Date
2019-04-26T06:25:48Z (6 years ago)
From
Ryan Foley at UC Santa Cruz <foley@ucsc.edu>
C. D. Kilpatrick, D. A. Coulter, C. Rojas-Bravo, J. S. Brown, G. Dimitriadis,
R. J. Foley, T. Hung, D. O. Jones, M. R. Siebert, K. Siellez (UCSC),
A. L. Piro (Carnegie), A. Rest (STScI), M. Drout (University of Toronto)
report on behalf of the One Meter, Two Hemisphere (1M2H) collaboration:
Using the 1-m Swope telescope at Las Campanas Observatory, we obtained
images of ZTF19aarzaod and ZTF19aarykkb (Kasliwal et al., GCN 24191) in the
localization region of LIGO/Virgo S190425z (LIGO-Virgo Collaboration,
GCN 24168). We processed the data using photpipe (Rest et al., 2005)
calibrating to the Pan-STARRS system (Chambers et al., 2016). We performed
PSF photometry on the images and did not perform any template subtraction.
Target | UTC | Filter | Mag (Err)
ZTF19aarykkb | 2019-04-26 04:23:04 | r | 18.4 (0.1)
ZTF19aarykkb | 2019-04-26 04:28:49 | i | 18.2 (0.1)
ZTF19aarykkb | 2019-04-26 04:34:45 | g | 19.2 (0.1)
ZTF19aarzaod | 2019-04-26 04:45:24 | r | 20.1 (0.1)
ZTF19aarzaod | 2019-04-26 04:56:44 | i | 19.5 (0.1)
Note: Given the level of background emission and lack of template subtractions,
we caution a systematic uncertainty of 0.1 mag.
We note that all fluxes are similar to previous reports (Hiramatsu et al.,
GCN 24194). In particular, we note that ZTF19aarykkb has a similar r-band
magnitude at 2019-04-25 17:53:45 UT (Tan et al., GCN 24193) and g-band
magnitude at 2019-04-25 19:21:09 UT (Hiramatsu et al., GCN 24194). We do not
see evidence for significant fading as reported by Bhalerao et al. (Bhalerao
et al., GCN 24201).
The reported photometry is consistent with SNe II at z ~ 0.025, as suggested
by their spectra (Pavana et al., GCN 24200; Perley et al., GCN 24204; Buckley
et al., GCN 24205; Izzo et al., GCN 24208; Wiersema et al., GCN 24209; Nicholl
et al., GCN 24211).
GCN Circular 24213
Subject
LIGO/Virgo S190425z: Insight-HXMT/HE observation
Date
2019-04-26T06:31:11Z (6 years ago)
From
Shuo Xiao at IHEP <xiaoshuo@ihep.ac.cn>
S. Xiao, Q. Luo, C. Cai, Q.B.Yi, C. K. Li, X. B. Li, G. Li, J. Y. Liao,
S. L. Xiong, C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang,
Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin,
Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song,
M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:
Insight-HXMT was taking data normally around the GW trigger time
(T0=2019-04-25 08:18:05.017 UTC). At T0, about 46% of the LIGO
localization region was covered by the Insight-HXMT without occultation
by the Earth.
Within T0 �� 100 s, no significant excess events (SNR > 3 sigma) are
found in a search of the Insight-HXMT/HE raw light curves.
Assuming the GW counterpart GRB with three typical GRB Band spectral
models, two typical duration timescales(1 s, 10 s) from the peak
position of the LIGO-Virgo location probability map, the 5-sigma
upper-limits fluence (0.2 - 5 MeV, incident energy) are reported below:
Band model 1 (alpha=-1.9, beta=-3.7, Ep=70 keV):
1s: 6.5e-08 erg cm^-2
10s: 1.9e-07 erg cm^-2
Band model 2 (alpha=-1.0, beta=-2.3, Ep=230 keV):
1s: 1.3e-07 erg cm^-2
10s: 3.0e-07 erg cm^-2
Band model 3 (alpha=-0.0, beta=-1.5, Ep=1000 keV):
1s: 4.0e-07 erg cm^-2
10s: 6.7e-07 erg cm^-2
Further analysis will be reported in the following circulars.
All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.
Insight-HXMT is the first Chinese space X-ray telescope, which was
fundedjointly by the China National Space Administration (CNSA) and
the Chinese Academy of Sciences (CAS).
More information could be found at: http://www.hxmt.org.
GCN Circular 24214
Subject
LIGO/Virgo S190425z: ZTF19aarzaod 1.5m OSN imaging and 10.4m GTC spectroscopy
Date
2019-04-26T06:32:04Z (6 years ago)
From
Alberto J. Castro-Tirado at IAA-CSIC <ajct@iaa.es>
A. J. Castro-Tirado, Y.-D. Hu, X.-Y. Li, E. Fernandez-Garcia and V.
Casanova (IAA-CSIC), A. F. Valeev and V. V. Sokolov (SAO-RAS), I.
Carrasco, A. Castellon and C. Perez del Pulgar (UMA), M. D.
Caballero-Garcia (ASU-CAS), S. B. Pandey (ARIES) and N. Castro-Rodriguez
(GRANTECAN, IAC, ULL), on behalf of a larger collaboration, report:
Following the report of the new transient ZTF19aarzaod (Kasliwal et al.,
GCN 24191) for the GW event S190425z (GCN 24168), we observed the target
with the 1.5m telescope at the Observatorio de Sierra Nevada (Spain),
measuring a R-band mag of 20.5 on Apr 26, 01:48 UT. An optical spectrum
(600s) covering the range 3700-7500 A was obtained with the 10.4m GTC
telescope equipped with OSIRIS in La Palma (Spain) on Apr 26, 03:40 UT.
It shows a red continuum with a broad emission consistent with being
H-alpha at the redshift of the host galaxy (z=0.0279) besides a narrow
H-beta emission line at a consistent redshift. Therefore we rule out the
relationship of ZTF19aarzaod to the GW event S190425z in agreement with
Buckley et al. (GCN 24205), Izzo et al. (GCN 24208), Wiersema (GCN
24209) and Nicholl et al. (GCN 24211).
We acknowledge the excellent support from the GTC staff.
GCN Circular 24215
Subject
LIGO/Virgo S190425z - ePESSTO+ NTT spectrum of candidate PS19qo
Date
2019-04-26T07:11:30Z (6 years ago)
From
Matt Nicholl at Royal Astronomical Soc. <mrn@roe.ac.uk>
P. Short, M. Nicholl (Edinburgh), S. J. Smartt, K. W. Smith (QUB), K. Chambers, M. Huber (IfA) , J. Anderson (ESO), T.-W. Chen (MPE), C. Inserra (Cardiff), O. Yaron (Weizmann), D. R. Young (QUB), C. Angus, M. Pursiainen, P. Wiseman (Southampton), S. Taubenberger (MPA), M. Gromadzki (Warsaw) on behalf of the ePESSTO+ collaboration
We observed PS19qo (Smith et al., GCN 24210) a potential counterpart to the gravitational wave trigger S190425z (GCN 24168), under the advanced Public ESO Spectroscopic Survey for Transient Objects (ePESSTO+; see Smartt et al. 2015, A&A, 579, 40 http://www.pessto.org). The observations were performed on the ESO New Technology Telescope at La Silla with the EFOSC2 instrument.
This candidate was chosen because of its apparent association with a cataloged galaxy at 199 Mpc. The NTT spectrum gives a good match to normal Type II SN at z=0.057.
GCN Circular 24216
Subject
LIGO/Virgo S190425z: KMTNet Observation
Date
2019-04-26T08:39:06Z (6 years ago)
From
Joonho Kim at Seoul National U. <joonho@astro.snu.ac.kr>
Joonho Kim (SNU), Myungshin Im (SNU), Chung-Uk Lee (KASI), Seung-Lee Kim
(KASI), Gregory S.H. Paek (SNU), Gu Lim (SNU), Sophia Kim (SNU), Sungyong
Hwang (SNU), Changsu Choi (SNU), Insu Paek (SNU), Suhyun Shin (SNU), Bomi
Park (SNU), Soojong Pak (KHU), Hyung Mok Lee (KASI), Hyun-Il Sung (KASI), on
behalf of a larger collaboration
We observed 120 host galaxy candidates in the 50% localization area of the BNS
merger candidate, S190425z, detected by LIGO/Virgo (GCN #24168) using the
KMTNet 1.6m telescopes at SSO, SAAO, and CTIO. The observation started at
2019-04-25 12:28 UT, and the images were taken in R-band with 120 sec
exposure time. No obvious transient has been identified. The list of
the targets
is given below.
16465757-1511349 16:48:57.00 -15:41:35.0
16483366-1520059 16:50:33.00 -15:50:06.0
17010310-1310184 17:03:03.00 -13:40:18.0
16372742-3044337 16:39:27.00 -31:14:34.0
16371371-2625123 16:39:13.00 -26:55:12.0
17033015-1301444 17:05:30.00 -13:31:44.0
17073219-1329173 17:09:32.00 -13:59:17.0
17432323-0325009 17:45:23.00 -03:55:01.0
16442971-2954301 16:46:29.00 -30:24:30.0
17404358-0608537 17:42:43.00 -06:38:54.0
17214929-0252202 17:23:49.00 -03:22:20.0
17042170-1300047 17:06:21.00 -13:30:05.0
16461237-0001563 16:48:12.00 00:31:56.0
17052059-1354058 17:07:20.00 -14:24:06.0
16551898-0715115 16:57:19.00 -07:45:12.0
16445871-0011441 16:46:58.00 00:41:44.0
17075556-0235287 17:09:55.00 -03:05:29.0
16365968-3055576 16:38:59.00 -31:25:58.0
17281431-0406583 17:30:14.00 -04:36:58.0
17343248-0659255 17:36:32.00 -07:29:26.0
16535846-2149010 16:55:58.00 -22:19:01.0
17081503-1333425 17:10:15.00 -14:03:43.0
16460002-1309243 16:48:00.00 -13:39:24.0
16350424-3054512 16:37:04.00 -31:24:51.0
16263236-3441507 16:28:32.00 -35:11:51.0
17222779-0505074 17:24:27.00 -05:35:07.0
16573248-2246391 16:59:32.00 -23:16:39.0
17030983-1247564 17:05:09.00 -13:17:56.0
17423503-0657581 17:44:35.00 -07:27:58.0
16473633-1509476 16:49:36.00 -15:39:48.0
16352839-2500426 16:37:28.00 -25:30:43.0
17161661-0811018 17:18:16.00 -08:41:02.0
17200620-0351381 17:22:06.00 -04:21:38.0
16512494-2254080 16:53:24.00 -23:24:08.0
16464891-0037544 16:48:48.00 -01:07:54.0
16452069-2037012 16:47:20.00 -21:07:01.0
16521781-2304586 16:54:17.00 -23:34:59.0
16495473-0636040 16:51:54.00 -07:06:04.0
17265688-0317354 17:28:56.00 -03:47:35.0
16471866-1456270 16:49:18.00 -15:26:27.0
17295066-0702448 17:31:50.00 -07:32:45.0
16532852-2312115 16:55:28.00 -23:42:12.0
16553496-0723587 16:57:35.00 -07:53:59.0
16435593-2529433 16:45:55.00 -25:59:43.0
17455093-0235298 17:47:50.00 -03:05:30.0
16563795-0712066 16:58:38.00 -07:42:07.0
04091988-5327483 04:11:19.00 -53:57:48.0
17073496-1637323 17:09:35.00 -17:07:32.0
17041344-1318227 17:06:13.00 -13:48:23.0
16440857-2854193 16:46:08.00 -29:24:19.0
16481805-1831303 16:50:18.00 -19:01:30.0
16545475-2329211 16:56:54.00 -23:59:21.0
17165559-0453060 17:18:55.00 -05:23:06.0
16502768+0005349 16:52:27.00 00:24:25.0
16550792-1801417 16:57:07.00 -18:31:42.0
16433259-2024343 16:45:32.00 -20:54:34.0
04171577-3858578 04:19:15.00 -39:28:58.0
16473469-2121514 16:49:34.00 -21:51:51.0
16301048-2822223 16:32:10.00 -28:52:22.0
17184030-0628489 17:20:40.00 -06:58:49.0
16480630-0037546 16:50:06.00 -01:07:55.0
17144035+0007545 17:16:40.00 00:22:05.0
04073433-5305504 04:09:34.00 -53:35:50.0
16482162-0407526 16:50:21.00 -04:37:53.0
17145452-1317481 17:16:54.00 -13:47:48.0
16472494-1813304 16:49:24.00 -18:43:30.0
16505041+0015538 16:52:50.00 00:14:06.0
16514833-1253444 16:53:48.00 -13:23:44.0
16553956-2238314 16:57:39.00 -23:08:31.0
16463548-2310136 16:48:35.00 -23:40:14.0
16595401-0445514 17:01:54.00 -05:15:51.0
16552065-0650095 16:57:20.00 -07:20:10.0
17235027-0820347 17:25:50.00 -08:50:35.0
17381357-0542425 17:40:13.00 -06:12:43.0
17475210-1053145 17:49:52.00 -11:23:15.0
17060471-1648304 17:08:04.00 -17:18:30.0
17465488-1053325 17:48:54.00 -11:23:33.0
17363676-0626500 17:38:36.00 -06:56:50.0
17420617-0926068 17:44:06.00 -09:56:07.0
16321778-3137378 16:34:17.00 -32:07:38.0
16501134-2227582 16:52:11.00 -22:57:58.0
16401811-2559083 16:42:18.00 -26:29:08.0
16305178-2811517 16:32:51.00 -28:41:52.0
16485650-2222422 16:50:56.00 -22:52:42.0
16461899-2105509 16:48:19.00 -21:35:51.0
17045066-1327563 17:06:50.00 -13:57:56.0
16500186-1754372 16:52:01.00 -18:24:37.0
16474585-2118434 16:49:45.00 -21:48:43.0
16480372-1159506 16:50:03.00 -12:29:51.0
04234351-3757099 04:25:43.00 -38:27:10.0
16402247-2211300 16:42:22.00 -22:41:30.0
16571736-1918597 16:59:17.00 -19:49:00.0
17080532-1638036 17:10:05.00 -17:08:04.0
17470574-0313407 17:49:05.00 -03:43:41.0
16501038-0833255 16:52:10.00 -09:03:26.0
17061698-0319254 17:08:17.00 -03:49:25.0
17012529-0757290 17:03:25.00 -08:27:29.0
16381154-3012590 16:40:11.00 -30:42:59.0
16435072-1829093 16:45:50.00 -18:59:09.0
17084763-1142374 17:10:47.00 -12:12:37.0
17275586-0352269 17:29:55.00 -04:22:27.0
16313752-2805243 16:33:37.00 -28:35:24.0
17211157-0330159 17:23:11.00 -04:00:16.0
17193554-0510154 17:21:35.00 -05:40:15.0
17282222-0311222 17:30:22.00 -03:41:22.0
16521779-1513294 16:54:17.00 -15:43:29.0
16433655-1750124 16:45:36.00 -18:20:12.0
16334229-3259350 16:35:42.00 -33:29:35.0
16392252-2303588 16:41:22.00 -23:33:59.0
17181392-0019465 17:20:13.00 00:49:47.0
17102195-0424569 17:12:22.00 -04:54:57.0
16522199-0744343 16:54:22.00 -08:14:34.0
17243739-0506362 17:26:37.00 -05:36:36.0
04005870-5341349 04:02:58.00 -54:11:35.0
16504578-2224476 16:52:45.00 -22:54:48.0
16280047-3312041 16:30:00.00 -33:42:04.0
16492033-1525363 16:51:20.00 -15:55:36.0
17453210-0452328 17:47:32.00 -05:22:33.0
17151656-1310140 17:17:16.00 -13:40:14.0
16554312-0420465 16:57:43.00 -04:50:47.0
--
--
Joonho Kim
joonho@astro.snu.ac.kr
Graduate Student,
Astronomy Program, Dept. of Physics & Astronomy,
Seoul National University, Seoul, Korea
���
GCN Circular 24217
Subject
LIGO/Virgo S190425z - ePESSTO+ spectrum of PS19qp shows red featureless source at z=0.037
Date
2019-04-26T09:24:50Z (6 years ago)
From
Matt Nicholl at Royal Astronomical Soc. <mrn@roe.ac.uk>
M. Nicholl, P. Short (Edinburgh), S. J. Smartt, K. W. Smith (QUB), K. Chambers, M. Huber (IfA) , J. Anderson (ESO), T.-W. Chen (MPE), C. Inserra (Cardiff), O. Yaron (Weizmann), D. R. Young (QUB), C. Angus, M. Pursiainen, P. Wiseman (Southampton), S. Taubenberger (MPA), M. Gromadzki (Warsaw) on behalf of the ePESSTO+ collaboration
We observed PS19qp (Smith et al., GCN 24210) a potential counterpart to the gravitational wave trigger S190425z (GCN 24168), under the advanced Public ESO Spectroscopic Survey for Transient Objects (ePESSTO+; see Smartt et al. 2015, A&A, 579, 40 http://www.pessto.org). The observations were performed on the ESO New Technology Telescope at La Silla with the EFOSC2 instrument.
The transient is coincident with a probable host galaxy 2MASS J17011849-0700102. Preliminary reduction of our NTT spectrum (1800s, Grism#13) shows a red and mostly featureless continuum, with a narrow H-alpha emission line, likely from the host galaxy, at z=0.037.
With this redshift and a foreground extinction of A_v = 1.3 mag (Schlafly & Finkbeiner 2011), the apparent magnitude of i=20.4 mag reported by Smith et al. corresponds to an absolute magnitude of -16.7. Further observations are in progress.
GCN Circular 24218
Subject
LIGO/Virgo S190425z: CALET Observations
Date
2019-04-26T11:09:39Z (6 years ago)
From
Valentin Pal'shin at AGU <val@phys.aoyama.ac.jp>
Y. Shimizu (Kanagawa U),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU),K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
T. Tamura (Kanagawa U), N. Cannady, M. L. Cherry (LSU),
S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena)
and the CALET collaboration:
At the trigger time of the compact binary merger candidate S190425z,
T0=2019-04-25 08:18:05.017 UTC (The LIGO Scientific Collaboration and
Virgo Collaboration, GCN Circ. 24168), the high-voltage of the CALET
Gamma-ray Burst Monitor (CGBM) detectors were off
(from T0-192 sec to T0+1084 sec).
The CALET Calorimeter (CAL) was operating in high energy trigger mode
at the trigger time of S190425z. Using the CAL data, we have searched for
gamma-ray events in the 10-100 GeV band within the time interval
T0 +/- 60 sec and found no candidates.
The 90% upper limit of CAL is 1.0x10^-4 erg/cm2/s (10-100 GeV) when
the summed LIGO-Virgo probability reaches 5%.
The CAL FOV was centered at RA=131.3 deg, Dec=-43.6 deg at T0.
GCN Circular 24219
Subject
LIGO/Virgo S190425z : IRSF/SIRIUS NIR photometry of ZTF19aarykkb and ZTF19aarzaod
Date
2019-04-26T11:27:51Z (6 years ago)
From
Kumiko Morihana at Nagoya University <morihana@u.phys.nagoya-u.ac.jp>
K. Morihana (Nagoya Univ.), M. Jian (Univ. of Tokyo), T. Nagayama (Kagoshima Univ.)
report on behalf of J-GEM collaboration:
We observed ZTF19aarykkb and ZTF19aarzaod reported by the Zwicky Transient Facility
(Kasliwal et al., GCN 24191) with the near-infrared (J, H, Ks) simultaneous imaging camera SIRIUS
attached to 1.4 m telescope IRSF (InfraRed Survey Facility) in Sutherland observatory, South Africa.
The observation started on 2019-04-26 00:19:13 UT. The exposure times in J-, H-, Ks-bands are
~30min (ZTF19aarykkb) and ~40 min (ZTF19aarzaod), respectively. We performed aperture photometry
and the magnitude are listed below. The photometric magnitudes may have an effect from the host
galaxy and nearest stars.
Target UTC J (err) H (err) Ks (err)
---------------------------------------------------------------------------------------------------
ZTF19aarykkb 2019-04-26 00:36:51.7 16.8 (0.1) 16.4 (0.1) 16.1 (0.1)
ZTF19aarzaod 2019-04-26 01:25:52.9 17.4 (0.1) 16.7 (0.1) 16.4 (0.1)
---------------------------------------------------------------------------------------------------
Given magnitudes were calibrated against 2MASS point sources (Vega System) in the field.
GCN Circular 24220
Subject
LIGO/Virgo S190425z: DCT ZTF19aarykkb spectroscopy
Date
2019-04-26T12:03:00Z (6 years ago)
From
Simone Dichiara at UMCP/NASA/GSFC <dichiara@umd.edu>
S.Dichiara (UMD, NASA-GSFC), P. Gatkine (UMD), J. Durbak (UMD),
E. Troja (UMD, NASA-GSFC), S.B. Cenko (NASA-GSFC), A. Kutyrev
(UMD, NASA-GSFC), S. Veilleux (UMD), report on behalf of a
larger collaboration:
We observed ZTF19aarykkb (Kasliwal et al., GCN 24191) using the the DeVeny
spectrograph mounted on the 4.3m Discovery Channel Telescope.
We obtained 22.5 min exposures at an average airmass of 1.5. Our spectra
cover
the wavelength range ~3,600-8,000 Angstrom.
A preliminary analysis our spectrum shows a bright emission line likely
associated to the H-alpha transition and a relatively featureless
continuum.
Overall our results are consistent with the reports from Pavana (GCN 24200)
and
Perley (GCN 24204).
We thank the staff of the Discovery Channel Telescope in particular Andrew
Hayslip,
Ishara Nisley for assistance with these observations. We also thank
Jennifer Hanley
for contributing her time.
GCN Circular 24222
Subject
LIGO/Virgo S190425z: LWA1 observations
Date
2019-04-26T13:39:10Z (6 years ago)
From
Christopher League at FRBSG <cleague@gmail.com>
C. League (LIU Brooklyn), M.J. Kavic (SUNY Old Westbury), J.H.
Simonetti (Virginia Tech), J. Dowell (U New Mexico), G.B. Taylor (U
New Mexico), J. Tsai, J. Kanner (Cal Tech), P. Shawhan (U Maryland),
C. Yancey (U Maryland)
The Long Wavelength Array (LWA1, located west of Socorro, New Mexico,
US) made beam-formed observations for 4 hours on April 25 following the
LVC_INITIAL notice S190425z (GCN 24168). Observations began at 09:02:43
UTC, about 2 minutes after the notice, which was ~45 minutes after the
detection.
The observations were centered at frequencies 25.85 MHz and 45.45 MHz,
each with a bandwidth of 19.6 MHz. The FWHM is 15.499 degrees at 25.85
MHz, and 6.648 degrees at 45.45 MHz.
The three beams were centered at RA 16.171h, Dec 22.831deg; RA
15.937h, Dec 26.110deg; RA 16.382h, Dec 19.313deg.
Data analysis is under way.
GCN Circular 24223
Subject
LIGO/Virgo S190425z: ZTF pre-merger limits on PS1 candidates
Date
2019-04-26T14:00:03Z (6 years ago)
From
Michael Coughlin at Caltech/LIGO <mcoughli@caltech.edu>
Authors: Michael W. Coughlin (Caltech), Shreya Anand (Caltech), Tomas
Ahumada (UMD)
On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of
Observatories Watching Transients Happen (GROWTH) collaborations
We have analyzed the list of objects reported in Smith et al. (24210),
and examined ZTF alerts for the same objects. We find that 7 of the
events listed below have recent, previous detections with ZTF prior to
the gravitational wave event trigger time and are likely unrelated to the
BNS event S190425z (The LIGO Scientific Collaboration and the Virgo
Collaboration, GCN 24168).
Name PS Name ZTF Name
AT2019ebu PS19pp ZTF19aasbgll
AT2019ebw PS19pq ZTF19aasazok
AT2019ecc PS19pw ZTF19aapwgpg
AT2019eck PS19qe ZTF19aapfrrw
AT2019ecl PS19qg ZTF19aasgwnp
AT2019ebr PS19qj ZTF18aaoxrvr
AT2019ebo PS19qn ZTF19aarpgau
ZTF and GROWTH are worldwide collaborations comprising Caltech, USA;
IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA;
DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; TTU USA;
Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, UK and USyd, Australia. ZTF
acknowledges the generous support of the NSF under AST MSIP Grant No
1440341. GROWTH acknowledges generous support of the NSF under PIRE
Grant No 1545949. Alert distribution service provided by DIRAC@UW
(Patterson et al. 2019). Alert filtering and follow-up co-ordination
is being undertaken by the GROWTH marshal system (Kasliwal et al.
2019).
--
Michael Coughlin
David and Ellen Lee Prize Postdoctoral Fellow
LIGO Laboratory
West Bridge, Rm. 257
California Institute of Technology
MC 100-36
Pasadena, CA 91125
email: mcoughli@ligo.caltech.edu
website: http://www.michaelwcoughlin.com
phone: +1 952 836 7113
GCN Circular 24224
Subject
LIGO/Virgo S190425z: GOTO observations
Date
2019-04-26T15:01:12Z (6 years ago)
From
Danny Steeghs at U.of Warwick/GOTO <dsteeghs@gmail.com>
D.Steeghs(1), Lyman, J. (1), M.Dyer(3), D.Galloway(2), V.Dhillon(3),
P.O'Brien(4), G.Ramsay(5), D.Pollacco(1), E.Thrane(2),
S.Poshyachinda(6), E.Palle(7), K.Ulaczyk(1), R.Cutter(1),
A.Levan(1), T. Marsh(1), R.West(1), K.Wiersema(1), B.Gompertz(1),
E.Stanway(1), K.Ackley(2), A.Obradovic(2), Y-L.Mong(2), A.Casey(2),
M.Brown(2), E.Rol(2), J.Mullaney(3), S.Littlefair(3),
L.Makrygianni(3), E.Daw(3), J.Maund(3), R.Starling(4), R.Eyles(4),
U.Sawangwit(6), D.Mkrtichian(6), S.Awiphan(6),S.Aukkaravittayapun(6),
P.Irawati(6), M.Kennedy(8), R.Breton(8), D.Mata-Sanchez(8),
T.Heikkila(9), R.Kotak(9)
(1) Warwick University; (2) Monash University; (3) Univ. of Sheffield;
(4) University of Leicester; (5) Armagh Observatory;
(6) National Astronomical Research Institute of Thailand;
(7) Instituto de Astrofisica de Canarias; (8) Univ. of Manchester;
(9) University of Turku
report on behalf of the GOTO collaboration:
We report on optical observations with the Gravitational-wave Optical
Transient Observer in response to the BNS event S190425z (GCN #24168).
Targeted observations across 136 pointings containing 29.6% of the
source location probability across 2,134 sqr. degrees (based on the
initial BAYESTAR skymap) were performed between 20:38 UT Apr 25 and
05:33 UT Apr 26 2019.
Each pointing spans 4.9x3.7 square degrees and consisted of 3x60s
exposures in our L-band filter (400-700nm passband) with typical
5-sigma photometric depth of g=20.1, based on a photometric
calibration against PS1 sources. A coverage map is available at
http://goto-observatory.warwick.ac.uk/S190425z.html
Images are processed immediately after acquisition using the GOTOphoto
pipeline. Difference imaging was performed on the median of each
triplet of exposures using recent survey observations of the same
pointings. Source candidates were initially filtered using a
classifier and cross-matched against a variety of catalogs, including
the MPC and PS1. Human candidate vetting was performed during data
acquisition and processing in case of notable detections.
We recover a number of known/already reported transients and variable
objects, but no new candidates were detected that could be credibly
associated with S190425z.
Our coverage includes some of the PS1 candidates (Smith et al. GCN
#24210), but we did not cover the position of AT2019ebq/PS19qp, which
remains an object of interest (Jonker et al. GCN #24221 ; Coughlin et
al. GCN #24223).
We also reviewed the locations of the marginal ATLAS candidates
reported in McBrien et al. (GCN #24197), but detect no sources at
these locations, in line with Perley et al. (GCN #24202). The 5-sigma
limits are provided below.
Name | IAU Name | Obs. MJD | Image lim mag (L band 5sig)
ATLAS19hxm | AT2019dzv | 58598.96 | 20.08
ATLAS19hyx | AT2019ebl | 58599.03 | 20.63
ATLAS19hyo | AT2019eao | 58598.93 | 20.50
ATLAS19hwn | AT2019ebm | 58598.89 | 20.65
ATLAS19hwh | AT2019ebn | 58598.96 | 20.67
GOTO is operated at the La Palma observing facilities of the
University of Warwick on behalf of a consortium including the
University of Warwick, Monash University, Armagh Observatory, the
University of Leicester, the University of Sheffield, the National
Astronomical Research Institute of Thailand (NARIT) and the Instituto
de Astrofisica de Canarias (IAC) (https://goto-observatory.org/)
GCN Circular 24225
Subject
LIGO/Virgo S190425z: Las Cumbres Observatory Galaxy Targeted Counterpart Search
Date
2019-04-26T15:02:05Z (6 years ago)
From
Daichi Hiramatsu at Las Cumbres Observatory <dhiramatsu@lco.global>
Daichi Hiramatsu (LCO/UCSB), Craig Pellegrino (LCO/UCSB), Jamison Burke
(LCO/UCSB), D. Andrew Howell (LCO/UCSB), Iair Arcavi (Tel Aviv University),
Curtis McCully (LCO) on behalf of the Las Cumbres GW Follow-up Collaboration
We report 300s gri-band images of the following galaxies in the LIGO/Virgo
S190425z localization region (GCN 24168) with the Las Cumbres Observatory
1m telescopes at Sutherland, South Africa. We find no obvious candidates
after performing image subtraction using SDSS images as templates.
Name RA(J2000) DEC(J200) Time(UT) Filter Limmag
CSCG080-051 249.859940 +11.210459 2019-04-25 23:30:33 i 21.4
2MASXJ16542402-0953212 253.600113 -9.889244 2019-04-25 21:36:06 i 21.0
2MASXJ16542402-0953212 253.600113 -9.889244 2019-04-25 21:41:48 r 21.8
2MASXJ16542402-0953212 253.600113 -9.889244 2019-04-25 21:47:30 g 22.4
CSCG137-046 242.315292 +25.712521 2019-04-25 22:16:57 i 20.8
CSCG137-046 242.315292 +25.712521 2019-04-25 22:22:38 r 21.6
CSCG137-046 242.315292 +25.712521 2019-04-25 22:28:19 g 22.5
NGC4555 188.921585 +26.522999 2019-04-25 19:49:40 i 21.8
NGC4555 188.921585 +26.522999 2019-04-25 19:55:21 r 22.6
NGC4555 188.921585 +26.522999 2019-04-25 20:01:02 g 22.7
NGC4375 186.252045 +28.558516 2019-04-25 19:36:20 i 20.8
NGC4375 186.252045 +28.558516 2019-04-25 19:42:01 r 22.5
NGC4375 186.252045 +28.558516 2019-04-25 19:47:42 g 22.7
NGC4585 189.555481 +28.936903 2019-04-25 19:55:31 i 20.4
NGC4585 189.555481 +28.936903 2019-04-25 20:01:12 r 22.0
NGC4585 189.555481 +28.936903 2019-04-25 20:06:54 g 22.7
UGC10412 247.400574 +15.658440 2019-04-25 23:04:17 i 21.5
UGC10412 247.400574 +15.658440 2019-04-25 23:09:59 r 22.1
UGC10412 247.400574 +15.658440 2019-04-25 23:15:41 g 22.4
GCN Circular 24226
Subject
LIGO/Virgo S190425z: AMI-LA radio observations of two ZTF afterglow candidates.
Date
2019-04-26T15:26:53Z (6 years ago)
From
Lauren Rhodes at Oxford <lauren.rhodes@physics.ox.ac.uk>
L. Rhodes, R. Fender, D. Williams, J. Bright (Oxford), K. Mooley (NRAO, Caltech; Jansky Fellow), A Horesh (The Hebrew University of Jerusalem), Dave Green, David Titterington (MRAO) and the JAGWAR collaboration.
We observed the positions of the two reported GW190425z afterglow candidates from GCN 24191 with the AMI Large Array at 15GHz. We started observing the first candidate, ZTF19aarykkb, on 2019 April 26.04 for 3 hrs (0.70 days after the initial detection). The second transient reported, ZTF19aarzoad, was observed with AMI Large Array at 15GHz on 2019 April 26.17 for 3 hrs (0.82 days after the initial detection). Due to the size of the AMI beam, we are unable to spatially resolve either transient source from their respective proposed host galaxies. We acknowledge that these two sources have since been shown to be unrelated to the gravitational wave detection (GCNs 24204 & 24205).
Furthermore, we have scheduled an observation of the promising afterglow candidate: AT2019ebq (GCN 24210).
We thank the MRAO staff for scheduling these observations.
GCN Circular 24227
Subject
LIGO/Virgo S190425z: TAROT-GRANDMA observation report
Date
2019-04-26T15:29:32Z (6 years ago)
From
Martin Blazek at HETH/IAA-CSIC <alf@iaa.es>
M. Blazek (HETH/IAA-CSIC), N. Christensen (Artemis),
E. Howell (OzGrav-UWA), M. Vardosanidze (Iliauni), M. Boer (Artemis),
L. Eymar (Artemis), A. Klotz (IRAP), R. Laugier (Artemis),
K. Noysena (Artemis, IRAP), S. Antier (APC), S. Basa (LAM),
D. Corre (LAL), M. Coughlin (Caltech), D. Coward (OzGrav-UWA),
J.G. Ducoin (LAL), B. Gendre (OzGrav-UWA), P. Hello (LAL),
C. Lachaud (APC), N. Leroy (LAL), D. Turpin (NAOC), X. Wang (THU)
Report on behalf of the TAROT network and GRANDMA collaborations.
We performed tiled observations of LIGO/VIRGO event S190425z (GCN #24168)
with the TAROT-Reunion (Les Makes Observatory, La R��union Island, France)
telescope operating in clear filter.
The observation started on 04/25/19 14:56:19 UTC which corresponds
approximately to 6.65 hours after the GW trigger time.
We performed the following tiled observations :
+------------+------------+---------+---------+---------+
| TStart | TEnd | RA | DEC | Proba |
| [UTC] | [UTC] | [deg] | [deg] | [%] |
|------------+------------+---------+---------+---------|
| 2019-04-25 | 2019-04-25 | 194.595 | 30 | 0.2 |
| 14:56:19 | 22:29:56 | | | |
| 2019-04-25 | 2019-04-25 | 182.338 | 25.714 | 0.2 |
| 17:03:57 | 17:55:18 | | | |
| 2019-04-25 | 2019-04-25 | 189.73 | 30 | 0.3 |
| 17:16:58 | 21:51:14 | | | |
| 2019-04-25 | 2019-04-26 | 243.117 | 25.714 | 0.6 |
| 18:07:39 | 01:40:56 | | | |
| 2019-04-25 | 2019-04-26 | 246.076 | 21.429 | 0.7 |
| 18:20:49 | 01:09:32 | | | |
| 2019-04-25 | 2019-04-25 | 238.442 | 25.714 | 0.9 |
| 19:11:40 | 22:16:40 | | | |
| 2019-04-25 | 2019-04-26 | 241.519 | 21.429 | 0.7 |
| 19:43:51 | 00:18:12 | | | |
+------------+------------+---------+---------+---------+
The Probability refers to the 2D spatial probability of the GW skymap
enclosed in a given tile. Each tile is 4.2x4.2 degrees. These observations
cover about 3% of the cumulative probability of the skymap. The typical
3-sigma limiting magnitude for a two minutes exposure is 17 mag.
The coverage map is available at:
https://grandma-owncloud.lal.in2p3.fr/index.php/s/tZTxGSoCEMc4fwG
Optical transient candidates will be sent through another GCN
circular depending on our data analysis.
GRANDMA (Global Rapid Advanced Network Devoted to the Multi-messenger
Addicts) is a network of robotic telescopes connected all over the
world with both photometry and spectrometry capabilities for Time-
domain Astronomy (https://grandma.lal.in2p3.fr/). Details on the TAROT
telescopes are available on the GRANDMA web pages or on
http://tarot.obs-hp.fr/
GCN Circular 24228
Subject
LIGO/Virgo S190425z: Updated localization from LIGO and Virgo data
Date
2019-04-26T15:32:37Z (6 years ago)
From
Leo Singer at GSFC <leo.p.singer@nasa.gov>
The LIGO Scientific Collaboration and the Virgo Collaboration report:
We have re-analyzed LIGO data around the time of the compact binary
coalescence (CBC) candidate S190425z (GCN 24168). Parameter
estimation has been performed using LALInference [1] and a new sky
map, LALInference.fits.gz, is available for retrieval from the
GraceDB event page:
https://gracedb.ligo.org/superevents/S190425z
For the LALInference.fits.gz skymap, the 90% credible region is 7461
deg2. Marginalized over the whole sky, the a posteriori luminosity
distance estimate is 156 +/- 41 Mpc (a posteriori mean +/- standard
deviation). This is the preferred sky map at this time.
For further information about analysis methodology and the contents
of this alert, refer to the LIGO/Virgo Public Alerts User Guide
<https://emfollow.docs.ligo.org/userguide/>.
[1] Veitch et al. PRD 91, 042003 (2015)
GCN Circular 24229
Subject
LIGO/Virgo S190425z: GROND observations of AT2019ebq/PS19qp
Date
2019-04-26T15:36:25Z (6 years ago)
From
Ting-Wan Chen at MPE <jchen@mpe.mpg.de>
P. Schady (U.Bath), T.-W. Chen (MPE, Humboldt Fellow), T. Schweyer (MPE), D. B. Malesani (DAWN/NBI and DARK/NBI) and J. Bolmer (MPE) report:
We observed the field of the AT2019ebq/PS19qp (Smith et al., GCN #24210; Nicholl et al., GCN #24217; Jonker et al., GCN #24221) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile).
Observations started at 09:08 UT on 26 of April 2019, about 1.04 days after the GW S190425z detection (LIGO and Virgo Collaboration, GCN #24168), and were performed under seeing conditions of 1���.4, and at an average airmass of 1.3. We detect the candidate and based on 25 min of total exposure time in optical and 26 min in NIR, we derive the following preliminary magnitudes (all in the AB system):
r = 20.78 +/- 0.20 mag,
i = 20.00 +/- 0.15 mag, and
z = 19.60 +/- 0.15 mag.
The magnitudes are measured using aperture photometry with a small aperture size of 0".75. We caution that the object is blended with the galaxy nucleus, and that the removal of the variable and bright host background may introduce further systematic errors.
Given magnitudes are calibrated against Pan-STARRS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V) = 0.51 mag in the direction of the counterpart (Schlafly & Finkbeiner 2011).
We acknowledge excellent help in obtaining these data from the observer Jose Ignacio Vines and supporting astronomer Angela Hempel on La Silla.
GCN Circular 24230
Subject
LIGO/Virgo S190425z: J-GEM spectroscopic observations of AT2019ebq/PS19qp with Subaru/FOCAS
Date
2019-04-26T15:50:38Z (6 years ago)
From
Tomoki Morokuma at U of Tokyo <tmorokuma@ioa.s.u-tokyo.ac.jp>
Morokuma, T. (U. of Tokyo), Ohta, K. (Kyoto U.),
Yoshida, M., Aoki, K. (NAOJ/Subaru), Tanaka, M. (Tohoku U.),
Sasada, M., Nakaoka, T., Akitaya, H., Kawabata, K. S. (Hiroshima U.),
Itoh, R. (Bisei Astronomical Observatory), Utsumi, Y. (Stanford U./SLAC),
on behalf of J-GEM collaboration
We performed spectroscopic observations of AT2019ebq/PS19qp (Smith et
al. 2019, GCN, 24210), a possible counterpart to the gravitational wave
event S190425z, with the Faint Object Camera and Spectrograph (FOCAS;
Kashikawa et al. 2002, PASJ, 54, 819) on the 8.2-m Subaru Telescope. We
started our observations at UT 2019-04-26 13:43, about 1.2 days after
the event.
We took a red part of optical spectrum, covering from 7,000 A to 10,000
A. At the redshift of z=0.037 (Nicholl et al. 2019, GCN, 24217; Jonker
et al. 2019, GCN, 24221), the spectrum shows a broad P-Cygni profile
with an absorption minimum around 8200 A and an emission peak around
8600 A. There is also another absorption feature around 7500 A. These
features can be attributed to the Ca II IR triplet and the O I 7774,
respectively. Therefore, this source is likely to be a reddened
supernova and unlikely to be associated with the gravitational wave event.
GCN Circular 24232
Subject
LIGO/Virgo S190425z: Nearby Galaxies in the Updated Localization Volume
Date
2019-04-26T16:12:25Z (6 years ago)
From
David Cook at IPAC/Caltech <dcook@ipac.caltech.edu>
LIGO/Virgo S190425z: Nearby Galaxies in the Updated Localization Volume
David O. Cook (Caltech/IPAC), Angela Van Sistine (UW Milwaukee), Leo Singer (NASA/GSFC), Igor Andreoni (Caltech), Michael Coughlin (Caltech), Bob Aloisi (UW Milwaukee), Patrick R. Brady (UW Milwaukee), Rick Ebert (Caltech/IPAC), George Helou (Caltech/IPAC), David Kaplan (UW Milwaukee), Mansi M. Kasliwal (Caltech), Joseph M. Mazzarella (Caltech/IPAC), and Marion Schmitz (Caltech/IPAC)
On behalf of the Global Relay of Observatories Watching Transients Happen (GROWTH) collaboration and the NASA/IPAC Extragalactic Database (NED) Team.
We spatially cross-matched the LIGO/Virgo S190425z (2-Update) trigger sky localization (90% containment volume) with the Census of the Local Universe (CLU; Cook et al. 2017; arxiv:1710.05016) galaxy catalog and found 56562 galaxies within the volume. The CLU catalog is a compilation of galaxies with existing redshifts from many sources (e.g., NED, SDSS, etc) and new galaxies from a 3PI steradian narrow-band survey to look for redshifted Halpha emission out to 200 Mpc with the Palomar Oschin 48-inch telescope (Cook et al. 2017; arxiv:1710.05016). We list here the top 20 CLU-matched galaxies sorted by stellar mass (Mstar) whose location on the sky and distance falls in the 90% volume reported by the BAYESTAR probability sky map (Singer et al. 2016). We also list the dust-corrected star formation rates (SFRs) for galaxies with GALEX FUV detections (a 'nan' for those with no detection).
For a more complete/extended list of galaxies in the 90% volume go to the NED Gravitational Wave Followup service at https://ned.ipac.caltech.edu/uri/NED::GWF/. This service provides downloadable galaxy lists and visualizations for candidate host galaxies. For each GW alert, these products are automatically generated and made available within minutes to expedite efficient electromagnetic followup observations. The NED top 20 list is sorted by 2MASS absolute K-band magnitude, but users can sort the entire list on a variety of other criteria (probability density, UV magnitudes, etc) after download.
name ra dec distmpc logsfr_fuv logmstar dP_dV
------------------------ -------- ------- ------- ---------- -------- --------
HIPASS J0029-15 7.3096 -15.0669 84.71 nan 13.25 3.03e-08
HIZOA J1822-21 275.5775 -21.1603 105.49 nan 12.52 1.02e-07
SDSS J125614.10+565225.3 194.0588 56.8737 170.72 nan 12.50 2.65e-08
2MASXi J0215532-232855 33.9721 -23.4821 155.60 nan 12.15 1.20e-07
2MASX J06090714+2150343 92.2798 21.8428 92.75 nan 12.14 1.37e-07
2MASX J05210136-2521450 80.2558 -25.3626 177.23 2.36 12.03 1.69e-07
FAIRALL 0009 20.9407 -58.8058 195.77 1.83 11.95 5.60e-08
LDCE 1285 271.5879 -25.4325 104.81 nan 11.92 3.44e-08
IRAS 05223+1908 81.3187 19.1794 123.16 nan 11.87 1.01e-07
ESO 250-G 012 63.2014 -46.6193 136.77 0.72 11.85 2.35e-07
ARK 120 79.0476 -0.1498 138.25 nan 11.83 2.01e-07
2MASX J04444356-4433487 71.1814 -44.5635 195.96 nan 11.80 4.98e-07
2MASX J17013663-2523008 255.4027 -25.3837 168.78 nan 11.79 3.41e-08
2MASS J17421439-0843195 265.5582 -8.7228 95.94 nan 11.71 4.74e-08
NGC 5995 237.1040 -13.7578 104.91 1.42 11.61 4.19e-08
CGCG 049-037 227.9241 4.4919 155.60 -0.73 11.51 2.52e-08
MRK 0486 234.1598 54.5592 193.00 nan 11.50 2.86e-08
LCRS B034324.7-394349 56.3022 -39.5748 178.14 1.09 11.47 3.70e-07
CGCG 219-058 213.2671 42.0054 170.39 0.18 11.47 9.93e-08
2MASS J17415525-1211566 265.4803 -12.1991 154.06 nan 11.45 3.03e-08
Table: Top 20 galaxies in CLU that fall in the 90% probability volume for S190425z (2-Update) sorted by stellar mass. Column descriptions are as follows. name: galaxy name. ra: RA (J2000, decimal degrees). dec: Dec (J2000, decimal degrees). distmpc: galaxy distance (Mpc). logsfr_fuv: log10 of the star formation rate (SFR, Msun per year), derived from GALEX All Sky Kron FUV magnitudes via the prescription of Murphy et al. (2011), corrected for internal dust extinction using a combination of GALEX FUV and 22um ALLWISE fluxes (Hao et al. 2011). logmstar: log10 of the galaxy stellar mass (Msun), estimated from 3.4um ALLWISE fluxes and a mass-to-light ratio of 0.5 (McGaugh & Schombert et al. 2015).
GCN Circular 24233
Subject
LIGO/Virgo S190425z: Keck NIR spectroscopy shows AT2019ebq is a supernova
Date
2019-04-26T16:12:30Z (6 years ago)
From
Kishalay De at Caltech, GROWTH <kde@astro.caltech.edu>
J. Jencson (Caltech), K. De (Caltech), S. Anand (Caltech), M. M.
Kasliwal (Caltech), I. Andreoni (Caltech), T. Ahumada (UMD), D. A.
Perley (LJMU) report on behalf of the ZTF and GROWTH collaborations
We obtained near-IR spectroscopy of AT2019ebq (GCN #24210) with the
Near-Infrared Echellette Spectrometer (NIRES) on the Keck II Telescope
on Mauna Kea. The spectrum shows broad P Cygni supernova-like features
including He I (10830 A) with a velocity of approx. 14000 km/s,
suggesting that this is a Type Ib/IIb supernova. Thus, this object is
unrelated to LIGO/Virgo S190425z (GCN #24168).
We thank the staff of Keck observatory, especially Percy Gomez and
Julie Renaud-Kim, and the observer, Wanqiu He, for facilitating this
Target of Opportunity observation.
GCN Circular 24234
Subject
LIGO/Virgo S190425z: YAHPT Optical Observation
Date
2019-04-26T16:14:19Z (6 years ago)
From
Tianrui Sun at Purple Mountain Obs,CAS <trsun@pmo.ac.cn>
Tianrui Sun,Jian Chen,Lei Hu,Fan Li, Ye Yuan, Yanning Fu, Yue Chen., Xuefeng Wu,Kelai Meng(PMO), Wen-xiong Li, Xinghan Zhang,Xiao-feng Wang(THU), Lifan Wang(PMO and TAMU)
We report the observations of the BAYESTAR skymap with GLADE catalogue of the BNS event S190425z,
(The LIGO Scientific Collaboration and the Virgo Collaboration, GCN 24168) with the Yaoan High Precision Telescope at Yaoan Observation Station(in Yunnan Province, China(101.1811�� E,25.528��N)), Purple Mountain Observatory.
We obtained images of ZTF19aarzaod and ZTF19aarykkb (Kasliwal et al., GCN 24191) in Rc band with exposure time 300s and calibrated to the PPMX catalogue. We performed image subtraction with template from PS1 r band images.
Object ObserveTime Band Mag(Magerr)
ZTF19aarykkb| 2019-04-25T19:10:32 |Rc | 18.33(0.08)
ZTF19aarykkb| 2019-04-25T19:15:47 |Rc | 18.33(0.08)
ZTF19aarykkb| 2019-04-25T19:21:03 |Rc | 18.00(0.12)
ZTF19aarykkb| 2019-04-25T19:26:18 |Rc | 18.39(0.09)
ZTF19aarykkb| 2019-04-25T19:31:34 |Rc | 18.29(0.08)
ZTF19aarykkb| 2019-04-25T20:12:02 |Rc | 18.28(0.08)
ZTF19aarykkb| 2019-04-25T20:33:53 |Rc | 18.35(0.08)
ZTF19aarykkb| 2019-04-25T21:06:48 |Rc | 18.15(0.14)
ZTF19aarykkb| 2019-04-25T21:17:44 |Rc | 18.04(0.12)
ZTF19aarykkb| 2019-04-25T21:28:46 |Rc | 18.09(0.11)
ZTF19aarykkb| 2019-04-25T21:39:43 |Rc | 18.00(0.12)
ZTF19aarykkb| 2019-04-25T21:50:34 |Rc | 18.04(0.12)
Object ObserveTime Band Type Mag(Magerr)
ZTF19aarzaod| 2019-04-25T19:47:31 |Rc |Mag Subtract | 18.98(0.59)
ZTF19aarzaod| 2019-04-25T21:34:10 |Rc |Mag Limit | 18.87(0.51)
ZTF19aarzaod| 2019-04-25T19:42:15 |Rc |Mag Limit | 18.97(0.40)
ZTF19aarzaod| 2019-04-25T21:45:01 |Rc |Mag Limit | 18.88(0.52)
ZTF19aarzaod| 2019-04-25T20:50:21 |Rc |Mag Subtract | 18.92(0.56)
ZTF19aarzaod| 2019-04-25T20:39:21 |Rc |Mag Limit | 18.98(0.52)
ZTF19aarzaod| 2019-04-25T20:28:20 |Rc |Mag Subtract | 18.96(0.60)
ZTF19aarzaod| 2019-04-25T21:01:16 |Rc |Mag Subtract | 18.88(0.52)
ZTF19aarzaod| 2019-04-25T21:23:13 |Rc |Mag Subtract | 18.91(0.61)
ZTF19aarzaod| 2019-04-25T21:12:12 |Rc |Mag Limit | 18.93(0.57)
ZTF19aarzaod| 2019-04-25T19:37:00 |Rc |Mag Limit | 18.99(0.55)
GCN Circular 24238
Subject
LIGO/Virgo S190425z: RATIR Observations of Galaxies
Date
2019-04-26T16:47:01Z (6 years ago)
From
Alan M Watson at UNAM <alan@astro.unam.mx>
Nat Butler (ASU), Alan M. Watson (UNAM), Eleonora Troja (GSFC/UMD), Rosa
L. Becerra (UNAM), Simone Dichiara (UMD), Diego Gonz��lez (UNAM),
Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), Margarita Pereyra
(UNAM), and Tanner Wolfram (ASU) report:
We observed 23 galaxies selected from the NED/CLU list with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on
the 1.5m Harold Johnson Telescope at the Observatorio Astron��mico
Nacional on Sierra San Pedro M��rtir on the night of 2019-04-26 UTC. For
each galaxy, we typically obtained 720 seconds of exposure in g and i filters
and 540 seconds of exposure in Y and H filters. Our observations are listed
below. Analysis is proceeding.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
Start (UTC) RA and Dec (J2000) Galaxy
2019-04-26 03:41 182.76301 +25.51679 2MASX J12110307+2530599
2019-04-26 04:01 188.30713 +27.58410 IC 3494
2019-04-26 04:17 182.16379 +25.12808 2MASX J12083929+2507410
2019-04-26 04:48 179.33521 +22.16242 KUG 1154+224
2019-04-26 05:06 180.72538 +21.64475 KUG 1200+219
2019-04-26 05:25 184.50847 +26.08058 2MASX J12180207+2604500
2019-04-26 05:43 183.01570 +25.11901 2MASX J12120382+2507083
2019-04-26 06:09 184.80208 +25.71502 IC 3146
2019-04-26 06:32 189.61375 +28.48008 2MASX J12382707+2828478
2019-04-26 06:52 180.98436 +22.98009 KUG 1201+232
2019-04-26 07:24 185.66534 +27.74699 IC 3230
2019-04-26 07:42 182.72627 +25.25279 2MASX J12105427+2515102
2019-04-26 08:03 181.75129 +22.38786 2MASX J12070031+2223161
2019-04-26 08:22 187.85341 +26.79614 IC 3450
2019-04-26 08:51 184.48819 +25.07652 IC 3116
2019-04-26 09:08 185.95186 +27.74630 KUG 1221+280
2019-04-26 09:25 184.27696 +27.19256 2MASX J12170644+2711335
2019-04-26 09:45 185.92750 +26.84897 2MASX J12234260+2650561
2019-04-26 10:11 184.87139 +25.89869 2MFGC9705
2019-04-26 10:30 190.76567 +30.38206 UGC 07891 NED01
2019-04-26 10:49 241.37454 +24.20486 2MASX J16052994+2412169
2019-04-26 11:08 241.33534 +23.48742 2MASX J16052050+2329146
2019-04-26 11:40 242.83681 +22.47378 2MASX J16112110+2228253
GCN Circular 24239
Subject
LIGO/Virgo S190425z: COATLI Observations of Galaxies
Date
2019-04-26T16:51:48Z (6 years ago)
From
Alan M Watson at UNAM <alan@astro.unam.mx>
Alan M. Watson (UNAM), Nat Butler (ASU), Eleonora Troja (GSFC/UMD), Rosa
L. Becerra (UNAM), Simone Dichiara (UMD), Diego Gonz��lez (UNAM),
Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), Margarita Pereyra
(UNAM), and Tanner Wolfram (ASU) report:
We observed 128 galaxies selected from the NED/CLU list with the COATLI
50-cm telescope and interim imager at the Observatorio Astron��mico
Nacional on the Sierra de San Pedro M��rtir
(http://coatli.astroscu.unam.mx) on the night of 2019-04-26 UTC. For
each galaxy, we typically obtained 150 seconds of exposure in the w
filter. Our observations are listed below. Analysis is proceeding.
We thank the COATLI technical team and the staff of the Observatorio
Astron��mico Nacional.
Start (UTC) RA and Dec (J2000) Galaxy
2019-04-26 03:44 182.7630 +25.5168 2MASX J12110307+2530599
2019-04-26 03:47 188.3071 +27.5841 IC 3494
2019-04-26 03:51 182.1638 +25.1281 2MASX J12083929+2507410
2019-04-26 03:54 179.3352 +22.1624 KUG 1154+224
2019-04-26 03:57 180.7254 +21.6448 KUG 1200+219
2019-04-26 04:01 184.5085 +26.0806 2MASX J12180207+2604500
2019-04-26 04:04 183.0157 +25.1190 2MASX J12120382+2507083
2019-04-26 04:10 184.8021 +25.7150 IC 3146
2019-04-26 04:14 189.6138 +28.4801 2MASX J12382707+2828478
2019-04-26 04:17 180.9844 +22.9801 KUG 1201+232
2019-04-26 04:21 185.6653 +27.7470 IC 3230
2019-04-26 04:24 182.7263 +25.2528 2MASX J12105427+2515102
2019-04-26 04:28 181.7513 +22.3879 2MASX J12070031+2223161
2019-04-26 04:31 187.8534 +26.7961 IC 3450
2019-04-26 04:34 184.4882 +25.0765 IC 3116
2019-04-26 04:38 185.9519 +27.7463 KUG 1221+280
2019-04-26 04:44 184.2770 +27.1926 2MASX J12170644+2711335
2019-04-26 04:48 185.9275 +26.8490 2MASX J12234260+2650561
2019-04-26 04:51 182.0900 +25.1909 2MASX J12082161+2511270
2019-04-26 04:55 184.8714 +25.8987 2MFGC 09705
2019-04-26 04:58 181.7447 +23.7051 2MASX J12065874+2342181
2019-04-26 05:01 190.7657 +30.3821 UGC 07891 NED01
2019-04-26 05:05 184.7850 +27.7624 2MASX J12190846+2745445
2019-04-26 05:08 182.9698 +25.4431 2MASX J12115275+2526352
2019-04-26 05:12 183.4407 +24.3560 2MASX J12134575+2421221
2019-04-26 05:18 241.3745 +24.2049 2MASX J16052994+2412169
2019-04-26 05:22 182.0299 +24.7903 2MASX J12080724+2447251
2019-04-26 05:25 185.1572 +26.1654 IC 3179
2019-04-26 05:29 192.7138 +31.0401 2MASX J12505128+3102236
2019-04-26 05:32 241.3353 +23.4874 2MASX J16052050+2329146
2019-04-26 05:36 186.2935 +25.8798 IC 3302
2019-04-26 05:39 242.8368 +22.4738 2MASX J16112110+2228253
2019-04-26 05:43 241.3670 +24.5229 2MASX J16052806+2431229
2019-04-26 05:46 179.5618 +21.8999 2MASX J11581481+2153594
2019-04-26 05:53 184.5249 +25.7112 2MASX J12180594+2542400
2019-04-26 05:57 178.7066 +22.1030 2MASX J11544958+2206106
2019-04-26 06:00 244.6924 +20.6921 2MASX J16184613+2041328
2019-04-26 06:04 186.4548 +26.7399 IC 3324
2019-04-26 06:07 188.9389 +30.0242 KUG 1233+302
2019-04-26 06:11 182.9716 +23.6437 2MASX J12115318+2338367
2019-04-26 06:14 236.4804 +26.9093 2MASX J15455527+2654333
2019-04-26 06:18 186.9607 +27.3807 2MASX J12275054+2722501
2019-04-26 06:22 187.9328 +26.8002 2MASX J12314393+2648008
2019-04-26 06:28 182.0403 +24.6768 2MASX J12080965+2440361
2019-04-26 06:31 245.7873 +20.0828 2MASX J16230893+2004582
2019-04-26 06:35 241.1113 +23.2575 2MASX J16042675+2315274
2019-04-26 06:38 244.4020 +20.8208 2MFGC 13087
2019-04-26 06:42 247.2044 +18.6858 2MASX J16284905+1841099
2019-04-26 06:45 188.2076 +28.9588 KUG 1230+292
2019-04-26 06:49 235.1367 +28.4220 2MASX J15403284+2825188
2019-04-26 06:53 244.5403 +21.5603 UGC 10321 NED04
2019-04-26 06:56 191.6240 +30.8486 2MASX J12462976+3050546
2019-04-26 07:02 184.7725 +27.2984 IC 3143
2019-04-26 07:06 241.1352 +23.9445 2MASX J16043249+2356393
2019-04-26 07:10 236.0194 +27.3464 2MASX J15440461+2720469
2019-04-26 07:13 182.1232 +25.2656 2MASX J12082949+2515560
2019-04-26 07:17 241.2167 +23.9408 2MASX J16045203+2356273
2019-04-26 07:20 185.7417 +28.4942 IC 3237
2019-04-26 07:24 243.1217 +22.6119 KUG 1610+227B
2019-04-26 07:28 234.3185 +29.9945 2MASX J15371644+2959397
2019-04-26 07:31 241.2392 +23.9076 2MASX J16045743+2354283
2019-04-26 07:37 232.4939 +30.9282 2MASX J15295860+3055425
2019-04-26 07:41 185.4638 +26.3636 IC 3206
2019-04-26 07:45 235.3756 +28.0977 2MASX J15413013+2805513
2019-04-26 07:48 242.5618 +22.2798 2MASX J16101484+2216471
2019-04-26 07:52 245.0006 +19.4868 2MASX J16200013+1929127
2019-04-26 07:55 244.5148 +19.8472 2MASX J16180359+1950499
2019-04-26 07:58 253.7886 -17.9404 2MASX J16550925-1756257
2019-04-26 08:02 183.6096 +24.1821 KUG 1211+244
2019-04-26 08:05 184.6317 +25.9993 2MASX J12183158+2559571
2019-04-26 08:12 244.9722 +18.8760 2MASX J16195329+1852337
2019-04-26 08:16 241.1951 +23.8051 2MASX J16044680+2348183
2019-04-26 08:19 186.7865 +28.9565 2MASX J12270877+2857229
2019-04-26 08:23 245.0050 +18.6073 2MASX J16200111+1836237
2019-04-26 08:27 244.4856 +19.1178 2MASX J16175654+1907039
2019-04-26 08:30 185.2458 +27.2876 2MASX J12205898+2717154
2019-04-26 08:34 183.4763 +25.1692 2MASX J12135424+2510091
2019-04-26 08:37 239.1263 +25.3290 2MASX J15563034+2519448
2019-04-26 08:41 240.9191 +24.9486 2MASX J16034054+2456555
2019-04-26 08:47 251.9904 -20.0771 2MASX J16475772-2004373
2019-04-26 08:51 244.6620 +19.1521 2MASX J16183883+1909079
2019-04-26 08:55 185.1663 +28.1220 2MASX J12203984+2807194
2019-04-26 08:58 242.6162 +23.7723 2MASX J16102788+2346201
2019-04-26 09:02 241.7240 +24.1507 2MASX J16065382+2409027
2019-04-26 09:05 244.5221 +21.5537 UGC 10321 NED01
2019-04-26 09:09 253.0308 -15.9408 2MASX J16520737-1556265
2019-04-26 09:12 245.5712 +18.6024 2MASX J16221705+1836088
2019-04-26 09:16 182.5894 +23.8117 2MASX J12102139+2348420
2019-04-26 09:22 248.6837 +17.1136 2MASX J16344407+1706482
2019-04-26 09:26 236.7935 +27.1077 2MASX J15471040+2706272
2019-04-26 09:29 247.7353 +16.5853 2MASX J16305646+1635074
2019-04-26 09:33 245.0037 +20.5053 2MASX J16200084+2030197
2019-04-26 09:36 241.1232 +24.1090 2MASX J16042959+2406323
2019-04-26 09:40 241.4533 +23.1037 2MASX J16054876+2306129
2019-04-26 09:44 252.6809 -17.3801 2MASX J16504342-1722483
2019-04-26 09:47 183.1095 +23.7284 2MASX J12122629+2343419
2019-04-26 09:51 244.5343 +20.9436 2MASX J16180824+2056369
2019-04-26 09:57 235.7265 +27.5767 2MASX J15425435+2734358
2019-04-26 10:01 242.2285 +24.3562 2MASX J16085484+2421220
2019-04-26 10:04 252.5841 -21.0833 2MASX J16502017-2105001
2019-04-26 10:08 244.0556 +20.4554 2MASX J16161336+2027191
2019-04-26 10:11 241.9449 +23.7905 2MASX J16074677+2347255
2019-04-26 10:15 234.6810 +29.4141 CGCG 166-023
2019-04-26 10:18 249.1245 +13.1593 2MASX J16362986+1309332
2019-04-26 10:22 241.2317 +23.9696 2MASX J16045560+2358113
2019-04-26 10:25 230.5441 +30.9400 2MASX J15221058+3056237
2019-04-26 10:31 240.5220 +25.7878 KUG 1559+259
2019-04-26 10:35 242.8522 +23.6745 2MASX J16112451+2340283
2019-04-26 10:38 245.7546 +20.4355 2MASX J16230105+2026072
2019-04-26 10:41 233.7091 +28.9272 2MASX J15345021+2855384
2019-04-26 10:45 248.9189 +13.1333 2MASX J16354056+1308003
2019-04-26 10:48 254.2265 -18.1893 2MASX J16565436-1811214
2019-04-26 10:52 245.1669 +18.8472 2MASX J16204007+1850497
2019-04-26 10:55 235.3256 +27.9190 2MASX J15411814+2755082
2019-04-26 10:59 238.8562 +25.5697 2MASX J15552546+2534107
2019-04-26 11:05 239.9639 +25.9146 2MASX J15595132+2554523
2019-04-26 11:09 235.4278 +28.0710 2MASX J15414267+2804162
2019-04-26 11:12 248.3433 +17.3044 2MASX J16332237+1718164
2019-04-26 11:15 235.3359 +27.7731 2MASX J15412065+2746242
2019-04-26 11:19 243.5524 +22.7777 2MASX J16141252+2246395
2019-04-26 11:22 239.2183 +24.9500 2MASX J15565239+2456597
2019-04-26 11:26 240.3571 +24.9833 KUG 1559+251
2019-04-26 11:29 241.2147 +23.9374 2MASX J16045152+2356153
2019-04-26 11:32 255.6592 -12.5202 2MASX J17023817-1231128
2019-04-26 11:39 241.8520 +22.5767 2MASX J16072447+2234356
2019-04-26 11:42 242.3100 +23.3823 2MASX J16091442+2322557
2019-04-26 11:46 235.2531 +28.3231 2MASX J15410076+2819224
2019-04-26 11:49 239.1760 +25.4779 2MASX J15564230+2528406
GCN Circular 24240
Subject
LIGO/Virgo S190425z: Pierre Auger Observatory follow-up
Date
2019-04-26T16:57:05Z (6 years ago)
From
Jaime Alvarez-Muniz at Pierre Auger Observatory <jaime.alvarezmuniz@gmail.com>
J. Alvarez-Muniz, F. Pedreira, E. Zas (Univ. Santiago de Compostela, Spain),
K. H. Kampert & M. Schimp (Bergische Universitat, Wuppertal, Germany)
on behalf of the Pierre Auger Collaboration.
In response to:
LIGO/Virgo GW trigger S190425z
T0=2019-04-25 08:18:05 UTC
We searched for Ultra-High-Energy (UHE) neutrinos with energies
above ~ 1e17 eV in data collected with the Surface Detector (SD)
of the Pierre Auger Observatory in a [-500,500] second interval
about the LIGO-Virgo trigger S1902425z as well as 1 day after it.
The field of view (fov) where the SD of Auger is sensitive to UHE
neutrinos (corresponding to inclined directions with respect to the
vertical relative to the ground) was PARTIALLY COINCIDENT (35.5%) with
the LIGO 90% localization region at the time T0 of the merger alert.
NO events survived the cuts applied to reject the background due
to UHE Cosmic Rays i.e. NO neutrino candidates were detected.
-------
The Pierre Auger Observatory is an UHE Cosmic Ray detector
located in the Mendoza Province in Argentina. It consists of
an array of Water Cherenkov detectors spread over a total surface
of 3000 km^2 arranged in a triangular grid of 1.5 km side as well
as Fluorescence telescopes and other systems
(see 10.1016/j.nima.2015.06.058 for more information).
For neutrino searches from GW events with Auger, please refer to:
https://journals.aps.org/prd/pdf/10.1103/PhysRevD.94.122007
GCN Circular 24241
Subject
Baksan Neutrino Observatory Alert 190405.62: Global MASTER-Net:LIGO/Virgo S190425z: PanSTARR OT AT2019ebq/PS19qp
Date
2019-04-26T17:32:58Z (6 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, D.Vlasenko, V.Vladimirov,
D.Zimnukhov,
A.Kuznetsov, P.Balanutsa, A. Chasovnikov, V.Topolev, D.Kuvshinov, F.Balakin
(Lomonosov Moscow State University, SAI, Physics Department),
V.B. Petkov, M.M. Boliev, A.N. Kurenya,
Baksan Neutrino Observatory, Institute for Nuclear Research of RAS,
Moscow, Russia
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres (The Instituto
de Astrofisica de Canarias),
D. Buckley (South African Astronomical Observatory),
O. Gress, N.M. Budnev, O.Ershova (Applied Physics Institute, Irkutsk State
University),
V. Yurkov, A. Gabovich, Yu. Sergienko, D. Kobcev (Blagoveschensk Educational
State University),
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov (Kislovodsk Solar Station
of the Pulkovo Observatory),
R. Podesta, C. Lopez, C.Francile, F. Podesta (Observatorio Astronomico Felix
Aguilar OAFA, San Juan National University),
H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE
SJNU)
MASTER Global Robotic Net (http://observ.pereplet.ru, Lipunov et al.,
2010,Advances in Astronomy,vol. 2010, 30L)
started LIGO/Virgo S190425z (Singer et al. GCN 24168)
inspection at 2019-04-25 09:10:18 UT (Lipunov et al. GCN 24167) at
MASTER-OAFA (Argentina).
MASTER-OAFA started PS19qp (Smith et al., GCN 24210 ) at 2019-04-26
01:56:40.
Looking at our old images AT2019ebq / PS19qp, we
found a very recent inspection of this field due to the neutrino BNO alert
3 weeks ago and automatical Circular (not published yet).
To establish a possible connection of this supernova with neutrinos, it is
extremely important to determine the age of the supernova AT2019ebq /
PS19qp . Thus the object is not associated with LIGO/Virgo S190425z but
may be connected with BNO Alert190405.62 .
Below you can find automatic Circular (not published yet):
MASTER-Kislovodsk robotic telescope (Global MASTER-Net:
http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy,
vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar
Station of Pulkovo observatory) was pointed to the BAKSAN Alert190405.62
( 17h 25m 36.00s , - 2d 36m 00.00s, R=3) 19864 sec after trigger time at
2019-04-05 20:29:29 UT, with upper limit up to 19.2 mag. The observations
began at zenit distance = 83 deg. The sun altitude is -39.9 deg.
MASTER-Tavrida robotic telescope located in Russia (Lomonosov MSU, SAI
Crimea astronomical station) was pointed to the BAKSAN Alert190405.62
28940 sec after trigger time at 2019-04-05 23:00:45 UT, with upper limit
up to 19.1 mag. The observations began at zenit distance = 63 deg. The
sun altitude is -37.1 deg.
MASTER-SAAO robotic telescope located in South Africa (South African
Astronomical Observatory) was pointed to the BAKSAN Alert190405.62 1 days
39324 sec after trigger time at 2019-04-07 01:53:49 UT, with upper limit
up to 19.2 mag. The observations began at zenit distance = 34 deg. The
sun altitude is -38.5 deg.
MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of
San Juan National University) was pointed to the BAKSAN Alert190405.62 1
days 54872 sec after trigger time at 2019-04-07 06:12:57 UT, with upper
limit up to 18.0 mag. The observations began at zenit distance = 49 deg.
The sun altitude is -56.9 deg.
The galactic latitude b = -60 deg., longitude l = 98 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=991224
The follow up spectral and photometric observations of AT2019ebq/PS19qp
are required.
This message may be cited
GCN Circular 24244
Subject
LIGO/Virgo S190425z: Further MMT Follow-Up Observations
Date
2019-04-26T18:37:16Z (6 years ago)
From
Griffin Hosseinzadeh at Harvard U <griffin.hosseinzadeh@cfa.harvard.edu>
G. Hosseinzadeh, E. Berger, P. K. Blanchard, T. Eftekhari, J. Gill,
S. Gomez, L. Patton, V. A. Villar, P. K. G. Williams (Harvard U),
P. S. Cowperthwaite (Carnegie Obs), R. Chornock (Ohio U), W. Fong,
R. Margutti (Northwestern U), and M. Nicholl (U Edinburgh) report:
We obtained 30 s i-band images of the following GLADE galaxies (Dalya
et al. 2018, MNRAS, 479, 2374) in the LIGO/Virgo localization region of
S190425z (GCN 24168) with the MMTCam instrument on the MMT 6.5-m telescope:
Name R.A. Dec. Date UT
16590728-0544311 254.780334 -5.741986 2019-04-26 08:30:29.18
58987.0 251.852000 -20.141740 2019-04-26 08:32:14.13
NGC6224 252.077301 6.312206 2019-04-26 08:34:11.44
NGC6051 241.236267 23.932871 2019-04-26 08:36:36.52
IC4572 235.475815 28.134085 2019-04-26 08:40:22.72
UGC10320 244.530502 21.066381 2019-04-26 08:44:29.81
IC4569 235.201462 28.292059 2019-04-26 08:47:01.76
57607 243.740997 21.938314 2019-04-26 08:50:10.58
57472 243.084732 23.001947 2019-04-26 08:51:40.62
IC1219 246.114319 19.482584 2019-04-26 08:53:28.45
UGC10412 247.400574 15.658440 2019-04-26 08:55:23.95
NGC6001 236.941498 28.641853 2019-04-26 08:57:41.17
55883 235.941849 28.415155 2019-04-26 08:59:38.86
57645 243.925613 19.637508 2019-04-26 09:02:13.12
59121 252.840240 7.862305 2019-04-26 09:04:08.24
56949 241.148224 25.189823 2019-04-26 09:06:30.33
58860 251.038666 7.445273 2019-04-26 09:08:30.08
57542 243.441711 22.918877 2019-04-26 09:10:43.92
UGC10224 242.209320 22.042635 2019-04-26 09:13:35.96
58097 246.408646 16.455000 2019-04-26 09:16:56.83
1717114 241.067825 24.812338 2019-04-26 09:18:57.27
59239.0 253.600113 -9.889244 2019-04-26 09:22:17.77
UGC10260 242.991150 20.923468 2019-04-26 09:25:28.05
IC4570 235.343994 28.229799 2019-04-26 09:28:54.53
UGC10035 236.901474 26.063671 2019-04-26 09:42:06.86
57692 244.190460 19.521360 2019-04-26 09:46:51.23
16505342-1500143 252.722595 -15.003985 2019-04-26 09:49:19.19
NGC6240 253.245255 2.400985 2019-04-26 09:51:26.55
UGC10360 245.797256 16.932606 2019-04-26 09:53:38.27
55774 235.152664 28.512449 2019-04-26 09:56:11.90
58735 250.167572 14.351479 2019-04-26 09:58:49.71
IC4621 252.713272 8.783868 2019-04-26 10:00:50.14
NGC6075 242.844025 23.965147 2019-04-26 10:04:43.26
16582619-0319463 254.609146 -3.329548 2019-04-26 10:11:41.89
16073961+2220315 241.915070 22.342087 2019-04-26 10:15:39.64
58028 246.063141 20.183607 2019-04-26 10:17:29.71
54895.0 230.687134 29.769716 2019-04-26 10:19:52.41
IC4505 221.639069 33.408661 2019-04-26 10:21:51.85
58768 250.337082 8.909049 2019-04-26 10:24:47.75
55373 233.193909 28.367073 2019-04-26 10:27:25.07
IC4587 239.965057 25.940653 2019-04-26 10:29:21.52
UGC08145 195.576172 32.890778 2019-04-26 10:31:26.07
57293 242.276917 24.870296 2019-04-26 10:35:04.99
16540875-0738073 253.536499 -7.635365 2019-04-26 10:38:59.44
52138 218.826752 35.118813 2019-04-26 10:41:49.85
16153554+1927123 243.898087 19.453444 2019-04-26 10:44:25.24
59338.0 254.524000 -21.274100 2019-04-26 10:46:46.58
UGC09233 216.145950 35.279827 2019-04-26 10:50:02.28
56421 239.016144 24.447973 2019-04-26 10:52:11.64
1484188 247.218430 15.420772 2019-04-26 10:54:30.92
Comparison of the images to the PS1 3pi survey (Chambers et al. 2016,
arXiv:1612.05560) reveals no new sources brighter than ~21 mag within
the 2.7 arcmin field of view.
We thank Chun Ly and Ben Kunk at MMT for taking these observations and
Dallan Porter for help with the target submission.
GCN Circular 24252
Subject
LIGO/Virgo S190425z: GRAWITA LBT spectroscopic observations
Date
2019-04-26T23:36:31Z (6 years ago)
Edited On
2025-04-09T18:46:36Z (2 months ago)
From
Roberta Carini at INAF <roberta.carini@inaf.it>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Tyler Barna at University of Minnesota <tylerpbarna@gmail.com>
R. Carini (INAF-OAR), L. Izzo (IAA), E. Palazzi (INAF-OAS), D. Sand (U of
Arizona), A. Rossi (INAF-OAS), L. Cassar�� (INAF-IASF Mi), A. Gargiulo
(INAF-IASF Mi), P. D'Avanzo (INAF-OAB), A. Melandri (INAF-OAB), L.
Tomasella (INAF-OAPd), S. Benetti (INAF-OAPd), M.T. Botticella
(INAF-OAC), M. Branchesi (GSSI), V. D'Elia (ASI-SSDC), E. Brocato
(INAF-OAAb, INAF-OAR), M. Della Valle (INAF-OAPd), G. Greco (Univ.
Urbino), O. Kuhn (LBTO), I. Shivaei (U of Arizona), X. Fan (U of
Arizona), J. Andrews (U of Arizona), W.-F. Fong (Northwestern), K. Paterson
(Northwestern), M. Lundquist (U of Arizona), F. Cusano (INAF-OAS) on behalf
of GRAWITA report:
We observed the transient source AT2019ebq/PS19qp reported by Pan-STARRS
(Smith, et al., GCN 24210) within the skymap of the GW event S190425z (GCN
24168) with the two 8.4 m telescopes of the Large Binocular Telescope (LBT,
Mount Graham, Arizona) equipped with the MODS1 and MODS2 cameras in
spectroscopic mode. The observations started on 2019-04-26 at 11:00:44 UT.
Four optical spectra, lasting 600 s each, were obtained using the dual
grating (wavelength range ~ 320-1000 nm).
The combined spectrum has a low S/N. A classification attempt performed
with GELATO (Harutyunyan et al., 2008, A&A, 488, 383) shows that the
spectrum is similar to those of type Ib/c SNe few days after the maximum.
Our results are in agreement with the findings of Morokuma et al. (GCN
24230) and Jencson et al. (GCN 24233).
We thank the LBT team for the observations.
[GCN OPS NOTE(27apr19): Per author's request, Kuhn's affilliation was changed
to LBTO.]
GCN Circular 24256
Subject
LIGO/Virgo S190425z: GRANDMA follow-up observations with Les Makes-T60, AZT-8 and Abastumani-T70
Date
2019-04-27T01:32:21Z (6 years ago)
From
Alexander Kann at IAA-CSIC <kann@iaa.es>
E. Howell (OzGrav-UWA), N. Christensen (Artemis), M. Blazek
(HETH/IAA-CSIC), M. Vardosanidze (Iliauni), A. Klotz (IRAP), J. P. Teng
(AGORA), S. Perrigault (AGORA), P. Thierry (Auragne obs.), P. Fock-Hang
(AGORA), A. Baransky (Kyiv univ), K. Barynova (Kyiv univ), A. Simon
(ASPD TSNUK), V. Vasylenko (Kyiv univ), V.Aivazyan (Iliauni), S. Beradze
(Iliauni), R. Inasaridze (Iliauni), N. Kochiashvili (Iliauni), R.
Natsvlishvili (Iliauni), G. Kapanadze (Iliauni), S. Antier (APC), S.
Basa (LAM), M. Boer (Artemis), D. Corre (LAL), M. Coughlin (Caltech), D.
Coward (OzGrav-UWA), J.G. Ducoin (LAL), B. Gendre (OzGrav-UWA), P. Hello
(LAL), C. Lachaud (APC), N. Leroy (LAL), D. Turpin (NAOC), X. Wang
(THU), and X. Zhang (THU)
report on behalf of the Les Makes, Abastumani, Lisnyky and GRANDMA
collaborations.
We performed galaxy-targeted observations of the LIGO/Virgo S190425z
event (GCN #24168) with the Les Makes-T60 telescope located in La
Reunion-France, Abastumani-T70 telescope located in Abastumani
Astrophysical Observatory, and AZT-8 telescope located in Observational
Station Lisnyky of TSNU of Kyiv.
The target galaxies are selected from the list of potential host
galaxies from the GLADE catalog in the 90% credible area of the
localization region of the LIGO/Virgo GW event. Note that these galaxies
are compatible within 3 sigma for the distance given by GW event.
The list of the galaxies we observed is shown in the tables below.
TStart and TEnd refers respectively to the time of the first and last
exposure for a given galaxy. Observations are not necessarily continuous
in this interval.
Les Makes-T60 cm imaged 52 galaxies in clear filter. The observation
started on 04/25/19 15:18:10 UTC which corresponds approximately to 421
minutes after the GW trigger time. The typical limiting magnitude is
19.2 for a 180 s exposure.
+------------+------------+-----------------------+-------+--------+------+
| TStart | TEnd | Galaxy | RA | DEC |
Dist.|
| [UTC] | [UTC] | name | [deg] | [deg] |
[Mpc]|
|------------+------------+-----------------------+-------+--------+------|
| 2019-04-25 | 2019-04-25 | GWGC [MFB2005] |182.081| 25.233 |
105.2|
| 15:18:10 | 15:33:35 | J120819.37+251357.9 | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA |181.979| 25.017 |
106.3|
| 15:34:40 | 15:50:05 |SDSSJ120754.97+250102.6| | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA |181.978| 25.101 | 111
|
| 15:34:40 | 15:50:05 |SDSSJ120754.70+250604.8| | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 38516 |182.038| 25.079 |
111.7|
| 15:34:40 | 15:50:05 | | | |
|
| 2019-04-25 | 2019-04-26 | HyperLEDA 1109773 |254.435| -1.799 |
136.9|
| 21:58:35 | 00:50:20 | | | |
|
| 2019-04-25 | 2019-04-26 | 2MASS 16574427-0147567|254.434| -1.799 |
136.4|
| 21:58:35 | 00:50:20 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16573561-0147457|254.398| -1.796 |
142.6|
| 21:58:35 | 22:14:00 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1109835 |254.399| -1.796 |
145.1|
| 21:58:35 | 22:14:00 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16572382-0147498|254.349| -1.797 |
147.9|
| 21:58:35 | 22:14:00 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1110982 |254.423| -1.754 |
148.8|
| 21:58:35 | 22:14:00 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1109807 |254.349| -1.797 |
148.8|
| 21:58:35 | 22:14:00 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16574141-0145157|254.423| -1.754 |
168.5|
| 21:58:35 | 22:14:00 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1106076 |254.456| -1.934 |
136.3|
| 22:14:10 | 22:29:35 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16574955-0156027|254.456| -1.934 |
135.6|
| 22:14:10 | 22:29:35 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16573281-0138287|254.387| -1.641 |
157.3|
| 22:29:45 | 22:45:10 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16570522-0151022|254.272| -1.851 |
147.2|
| 22:45:21 | 23:00:46 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1107232 |254.346| -1.89 |
148.8|
| 22:45:21 | 23:00:46 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1109171 |254.296| -1.82 |
148.8|
| 22:45:21 | 23:00:46 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16572303-0153258|254.346| -1.891 |
155.8|
| 22:45:21 | 23:00:46 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16571094-0149128|254.296| -1.82 |
169.9|
| 22:45:21 | 23:00:46 | | | |
|
| 2019-04-25 | 2019-04-26 | 2MASS 16580368-0150074|254.515| -1.835 |
147.5|
| 23:00:56 | 00:50:20 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1108643 |254.598| -1.839 |
136.9|
| 23:00:56 | 23:16:21 | | | |
|
| 2019-04-25 | 2019-04-26 | 2MASS 16580515-0149544|254.521| -1.832 |
162.3|
| 23:00:56 | 00:50:20 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16585823-0202277|254.743| -2.041 |
132.1|
| 23:16:31 | 23:31:56 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 161011 |254.743| -2.041 | 145
|
| 23:16:31 | 23:31:56 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 161014 |254.822| -2.074 |
120.5|
| 23:16:31 | 23:31:56 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16591729-0204281|254.822| -2.074 |
107.3|
| 23:16:31 | 23:31:56 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 161013 |254.775| -1.914 |
133.6|
| 23:32:06 | 23:47:31 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16592042-0153111|254.835| -1.886 | 147
|
| 23:32:06 | 23:47:31 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 161015 |254.835| -1.886 |
148.1|
| 23:32:06 | 23:47:31 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16590588-0154501|254.775| -1.914 |
128.1|
| 23:32:06 | 23:47:31 | | | |
|
| 2019-04-25 | 2019-04-26 | HyperLEDA |253.592| -16.81 |
122.3|
| 23:47:49 | 00:03:14 | 6dFJ1654221-164837 | | |
|
| 2019-04-25 | 2019-04-26 | 2MASS |253.592| -16.81 |
122.5|
| 23:47:49 | 00:03:14 | 16542215-1648370 | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1093975 |255.095| -2.372 |
140.4|
| 00:03:31 | 00:18:56 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 161019 |255.096| -2.326 |
143.6|
| 00:03:31 | 00:18:56 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1092764 |255.06 | -2.413 | 145
|
| 00:03:31 | 00:18:56 | | | |
|
| 2019-04-26 | 2019-04-26 | 2MASS 17002062-0225482|255.086| -2.43 |
145.6|
| 00:03:31 | 00:18:56 | | | |
|
| 2019-04-26 | 2019-04-26 | 2MASS 17002302-0219322|255.096| -2.326 | 129
|
| 00:03:31 | 00:18:56 | | | |
|
| 2019-04-26 | 2019-04-26 | 2MASS 17001441-0224462|255.06 | -2.413 |
147.4|
| 00:03:31 | 00:18:56 | | | |
|
| 2019-04-26 | 2019-04-26 | 2MASS 17002095-0217192|255.087| -2.289 |
151.5|
| 00:03:31 | 00:18:56 | | | |
|
| 2019-04-26 | 2019-04-26 | 2MASS 17002288-0222202|255.095| -2.372 |
120.1|
| 00:03:31 | 00:18:56 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 899699 |253.301| -16.316|
118.8|
| 00:19:13 | 00:34:38 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 899284 |253.355| -16.349|
118.8|
| 00:19:13 | 00:34:38 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 900018 |253.27 | -16.291|
122.8|
| 00:19:13 | 00:34:38 | | | |
|
| 2019-04-26 | 2019-04-26 | 2MASS 16530485-1617273|253.27 | -16.291| 123
|
| 00:19:13 | 00:34:38 | | | |
|
| 2019-04-26 | 2019-04-26 | 2MASS 16532193-1617132|253.341| -16.287|
129.8|
| 00:19:13 | 00:34:38 | | | |
|
| 2019-04-26 | 2019-04-26 | 2MASS 16531513-1621223|253.313| -16.356|
99.7|
| 00:19:13 | 00:34:38 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1109100 |254.506| -1.823 | 138
|
| 00:34:55 | 00:50:20 | | | |
|
| 2019-04-26 | 2019-04-26 | 2MASS 16580128-0149216|254.505| -1.823 |
136.4|
| 00:34:55 | 00:50:20 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 161003 |253.86 | -7.206 |
132.3|
| 00:50:34 | 01:05:59 | | | |
|
| 2019-04-26 | 2019-04-26 | 2MASS 16552449-0715255|253.852| -7.257 |
130.1|
| 00:50:34 | 01:05:59 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 161002 |253.852| -7.257 |
130.7|
| 00:50:34 | 01:05:59 | | | |
|
+------------+------------+-----------------------+-------+--------+------+
Abastumani-T70 imaged 41 galaxies in R filter. The observation started
on 04/25/19 23:08:01 UTC which corresponds approximately to 890 minutes
after the GW trigger time. The typical limiting magnitude is 16.5 for a
1 min exposure.
+------------+------------+-----------------------+-------+--------+------+
| TStart | TEnd | Galaxy | RA | DEC |
Dist.|
| [UTC] | [UTC] | name | [deg] | [deg] |
[Mpc]|
|------------+------------+-----------------------+-------+--------+------|
| 2019-04-25 | 2019-04-25 | GWGC UGC07124 |182.193| 24.946 |
100.5|
| 23:08:01 | 23:15:13 | | | |
|
| 2019-04-25 | 2019-04-25 | GWGC PGC038615 |182.325| 24.968 |
102.7|
| 23:08:01 | 23:15:13 | | | |
|
| 2019-04-25 | 2019-04-25 | GWGC PGC038526 |182.055| 24.943 |
105.7|
| 23:08:01 | 23:15:13 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1093975 |255.095| -2.372
140.4|
| 23:22:46 | 23:29:58 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 161019 |255.096| -2.326 |
143.6|
| 23:22:46 | 23:29:58 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1092764 |255.06 | -2.413 | 145
|
| 23:22:46 | 23:29:58 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 17002062-0225482|255.086| -2.43 |
145.6|
| 23:22:46 | 23:29:58 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 17002302-0219322|255.096| -2.326 | 129
|
| 23:22:46 | 23:29:58 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 17001441-0224462|255.06 | -2.413 |
147.4|
| 23:22:46 | 23:29:58 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 17002095-0217192|255.087| -2.289 |
151.5|
| 23:22:46 | 23:29:58 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 17002288-0222202|255.095| -2.372 |
120.1|
| 23:22:46 | 23:29:58 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 899699 |253.301| -16.316|
118.8|
| 23:37:08 | 23:44:20 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 899284 |253.355| -16.349|
118.8|
| 23:37:08 | 23:44:20 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 900018 |253.27 | -16.291|
122.8|
| 23:37:08 | 23:44:20 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16530485-1617273|253.27 | -16.291| 123
|
| 23:37:08 | 23:44:20 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16532193-1617132|253.341| -16.287|
129.8|
| 23:37:08 | 23:44:20 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16531513-1621223|253.313| -16.356|
99.7|
| 23:37:08 | 23:44:20 | | | |
|
| 2019-04-25 | 2019-04-26 | HyperLEDA |253.486| -16.12 |
121.9|
| 23:54:01 | 00:01:13 | 6dFJ1653567-160711 | | |
|
| 2019-04-25 | 2019-04-26 | 2MASS 16535674-1607110|253.486| -16.12 |
122.1|
| 23:54:01 | 00:01:13 | | | |
|
| 2019-04-25 | 2019-04-26 | 2MASS 16535385-1614537|253.474| -16.248|
109.3|
| 23:54:01 | 00:01:13 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 896696 |253.494| -16.552|
121.4|
| 00:04:49 | 00:12:01 | | | |
|
| 2019-04-26 | 2019-04-26 | 2MASS 17005715-0225086|255.238| -2.419 | 127
|
| 00:17:30 | 00:24:42 | | | |
|
| 2019-04-26 | 2019-04-26 | 2MASS 17012357-0220366|255.348| -2.344 |
146.1|
| 00:17:30 | 00:24:42 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1094718 |255.348| -2.344 |
150.5|
| 00:17:30 | 00:24:42 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1697461 |241.489| 23.986 |
148.8|
| 00:30:30 | 00:37:42 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1696139 |241.357| 23.92 |
136.9|
| 00:30:30 | 00:37:42 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA |235.784| 28.419 | 145
|
| 00:42:34 | 00:49:45 |SDSSJ154308.15+282509.9| | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1835553 |235.651| 28.432 |
143.7|
| 00:42:34 | 00:49:45 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1697264 |240.942| 23.977 |
157.7|
| 00:55:56 | 01:03:07 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1695306 |240.892| 23.875 |
153.6|
| 00:55:56 | 01:03:07 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 56887 |240.925| 24.095 |
140.9|
| 00:55:56 | 01:03:07 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 56963 |241.153| 23.663 |
165.5|
| 01:09:56 | 01:17:08 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1691288 |241.25 | 23.658 |
166.8|
| 01:09:56 | 01:17:08 | | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1693165 |241.235| 23.758 |
170.6|
| 01:09:56 | 01:17:08 | | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1690684 |241.15 | 23.625 |
163.5|
| 01:09:56 | 01:17:08 | | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 57021 |241.26 | 23.669 |
146.9|
| 01:09:56 | 01:17:08 | | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1690441 |241.184| 23.612 |
151.4|
| 01:09:56 | 01:17:08 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA |241.04 | 24.331 |
168.7|
| 01:21:42 | 01:28:54 |SDSSJ160409.58+241950.7| | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1706506 |240.988| 24.402 |
169.4|
| 01:21:42 | 01:28:54 | | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1706072 |241.077| 24.382 |
151.9|
| 01:21:42 | 01:28:54 | | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1703751 |241.076| 24.281 |
147.3|
| 01:21:42 | 01:28:54 | | | |
|
+------------+------------+-----------------------+-------+--------+------+
AZT-8 imaged 26 galaxies, in R and B filters. The observation started on
04/25/19 22:32:38 UTC which corresponds approximately to 855 minutes
after the GW trigger time. The typical limiting magnitude is 19.2 for a
20x30 s exposure.
+------------+------------+-----------------------+-------+--------+------+
| TStart | TEnd | Galaxy | RA | DEC |
Dist.|
| [UTC] | [UTC] | name | [deg] | [deg] |
[Mpc]|
|------------+------------+-----------------------+-------+--------+------|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1107232 |254.346| -1.89 |
148.8|
| 22:32:38 | 22:56:24 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16572303-0153258|254.346| -1.891 |
155.8|
| 22:32:38 | 22:56:24 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16570522-0151022|254.272| -1.851
147.2|
| 23:01:18 | 23:21:22 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1109171 |254.296| -1.82
148.8|
| 23:01:18 | 23:21:22 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16571094-0149128|254.296| -1.82 |
169.9|
| 23:01:18 | 23:21:22 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1109773 |254.435| -1.799 |
136.9|
| 23:24:57 | 23:45:08 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16574427-0147567|254.434| -1.799 |
136.4|
| 23:24:57 | 23:45:08 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16573561-0147457|254.398| -1.796 |
142.6|
| 23:24:57 | 23:45:08 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1109835 |254.399| -1.796 |
145.1|
| 23:24:57 | 23:45:08 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16572382-0147498|254.349| -1.797 |
147.9|
| 23:24:57 | 23:45:08 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1110982 |254.423| -1.754 |
148.8|
| 23:24:57 | 23:45:08 | | | |
|
| 2019-04-25 | 2019-04-25 | HyperLEDA 1109807 |254.349| -1.797 |
148.8|
| 23:24:57 | 23:45:08 | | | |
|
| 2019-04-25 | 2019-04-25 | 2MASS 16574141-0145157|254.423| -1.754 |
168.5|
| 23:24:57 | 23:45:08 | | | |
|
| 2019-04-25 | 2019-04-26 | HyperLEDA 1699170 |241.231| 24.073 |
165.3|
| 23:56:12 | 00:16:25 | | | |
|
| 2019-04-25 | 2019-04-26 | HyperLEDA |241.268| 24.045 |
154.1|
| 23:56:12 | 00:16:25 |SDSSJ160504.21+240240.4| | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 140564 |241.215| 23.938 |
161.5|
| 00:17:33 | 00:37:36 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1695387 |241.253| 23.879 |
154.2|
| 00:17:33 | 00:37:36 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA |241.229| 23.919 | 146
|
| 00:17:33 | 00:37:36 |SDSSJ160454.83+235507.5| | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 57003 |241.211| 23.975 |
176.2|
| 00:17:33 | 00:37:36 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA NGC6051 |241.236| 23.933 |
143.6|
| 00:17:33 | 00:37:36 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 57014 |241.248| 23.97 |
140.2|
| 00:17:33 | 00:37:36 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1697461 |241.489| 23.986 |
148.8|
| 00:40:37 | 01:01:06 | | | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA |241.333| 23.915 |
149.7|
| 01:03:45 | 01:24:03 |SDSSJ160519.85+235455.0| | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA |241.275| 23.874 |
175.9|
| 01:03:45 | 01:24:03 |SDSSJ160505.95+235227.2| | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA |241.301| 23.853 |
136.9|
| 01:03:45 | 01:24:03 |SDSSJ160512.22+235109.2| | |
|
| 2019-04-26 | 2019-04-26 | HyperLEDA 1696139 |241.357| 23.92 |
136.9|
| 01:03:45 | 01:24:03 | | | |
|
+------------+------------+-----------------------+-------+--------+------+
GRANDMA (Global Rapid Advanced Network Devoted to the Multi-messenger
Addicts) is a network of robotic telescopes connected all over the world
with both photometry and spectrometry capabilities for Time-domain
Astronomy (https://grandma.lal.in2p3.fr/). Details on the telescopes are
available on the GRANDMA web pages.
This circular is citable.
GCN Circular 24260
Subject
LIGO/Virgo S190425z: ANU 2.3m early observations of ZTF19aarykkb
Date
2019-04-27T04:34:58Z (6 years ago)
From
Seo-Won Chang at SkyMapper <seowon.chang@anu.edu.au>
Seo-Won Chang (ANU/OzGrav), Christian Wolf (ANU/OzGrav), Christopher A. Onken (ANU), Susan Scott (ANU/OzGrav), Christopher Lidman (ANU), J.Cooke (Swinburne), S.Webb (Swinburne), P.Gurri (Swinburne), T.Nordlander (ANU).
We obtained a series of early IFU spectra of the potential counterpart ZTF19aarykkb (Kasliwal et al., GCN 24191) to the GW candidate S190525z (GCN 24168) and host galaxy with the WiFeS instrument on the ANU2.3m telescope, located at Siding Springs Observatory, Australia. We acquired our first 850s exposure integration starting at UT 2019-04-25T17:40:40.5 together with 5x1200s spectra, using a configuration of R3000/RT560 covering the wavelength range of 330nm to 900nm. The spectrum appears to be a young Type II supernova, consistent with Pavana (GCN 24200), Perley (GCN 24204) and Dichiara (GCN 24220).
GCN Circular 24262
Subject
LIGO/Virgo S190425z: Additional Pan-STARRS transients in the skymap
Date
2019-04-27T05:22:15Z (6 years ago)
From
Ken Smith at Queen's University Belfast <k.w.smith@qub.ac.uk>
K. W. Smith, D. R. Young, O. McBrien, J. Gillanders. S. Srivastav,
S. J. Smartt, D. O'Neil, P. Clark, S. Sim (QUB), K. C. Chambers,
M. Huber, E. Magnier, A. Schultz, (IfA, Univ. Hawaii), L. Denneau,
H. Flewelling, A. Heinze, J. Tonry, H. Weiland, A. Rest (STScI),
B. Stalder (LSST), C. Stubbs (Harvard)
Due to delayed ingest of a small amount of data from the Pan-STARRS1 telescope
(Chambers et al. 2016, arXiv:1612.05560C), we report 5 candidates in addition
to those already announced in GCN 24210. bPC denotes the probability
contour within which the transient is found according to the S190425z LAL
Interference map (Singer, GCN 24228).
Name | TNS Name | RA (J2000) | Dec (J2000) | z | Disc mag | bPC | Notes
PS19qx | AT2019edd | 15:17:03.75 | +29:57:33.7 | | 20.92 i | 40 |
PS19qt | AT2019edc | 15:24:13.95 | +28:54:47.8 | 0.075 | 21.23 i | 50 | (1)
PS19qu | AT2019edf | 16:01:49.91 | +22:00:17.4 | | 20.90 i | 60 |
PS19qv | AT2019ecy | 16:14:20.12 | +31:21:20.3 | 0.179 | 21.08 i | 90 | (2)
PS19rg | AT2019eda | 16:25:34.93 | +34:08:40.8 | | 20.98 i | 90 |
NOTES
(1) Probable host is 2MASX J15241346+2854453 (NED)
(2) Probable host is SDSS J161420.36+312121.5 (NED)
Finders can be found at:
https://star.pst.qub.ac.uk/~kws/finders/S190425z/ps1_finders.tgz
GCN Circular 24266
Subject
LIGO/Virgo S190425z: Fermi-LAT search for a high-energy gamma-ray counterpart
Date
2019-04-27T07:43:09Z (6 years ago)
From
Magnus Axelsson at Stockholm U. <magaxe@kth.se>
M. Axelsson (KTH & Stockholm Univ.), E. Bissaldi (INFN and Politecnico Bari), D. Kocevski (NASA/MSFC), F. Longo (University and INFN, Trieste), and N. Omodei (Stanford Univ.) report on behalf of the Fermi-LAT Collaboration:
We have searched data collected by the Fermi Large Area Telescope (LAT) on April 25, 2019, for possible high-energy (E > 100 MeV) gamma-ray emission in spatial/temporal coincidence with the LIGO/Virgo trigger S190425z (GCN 24168).
We define "instantaneous coverage" as the integral over the region of the LIGO probability map that is within the LAT field of view at a given a time, and "cumulative coverage" as the integral of the instantaneous coverage over time. Fermi-LAT had instantaneous coverage of ~37% of the LIGO probability at the time of the trigger (T0 = 2019-04-25 08:18:05.017 UTC), and reached ~98% cumulative coverage after ~4 ks. Due to the observing pattern of Fermi, the remaining area was not observed for more than 24 hours after the trigger time of the event.
We performed a search for a transient counterpart within the observed region of the 90% contour of the LIGO map in a fixed time window from T0 to T0 + 10 ks.
Two significant excesses (with TS>25) were found at R.A., Dec. = 278.7, -21.1 and 57.2, -28.2, respectively, but they are associated with known sources currently flaring (PKS 1830-211 and PKS 0346-27).
We also performed a search which adapted the time interval of the analysis to the exposure of each region of the sky, and no additional excesses were found.
Energy flux upper bounds for the fixed time interval between 100 MeV and 100 GeV for this search vary between 0.7e-10 and 3.9e-8 [erg/cm^2/s].
The Fermi-LAT point of contact for this event is Magnus Axelsson (magaxe@kth.se<mailto:magaxe@kth.se>).
The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN Circular 24267
Subject
LIGO/Virgo S190425z: Lijiang 2.4-m Telescope Follow-up Observations
Date
2019-04-27T07:44:48Z (6 years ago)
From
Xiaofeng Wang at Tsinghua University <wang_xf@mail.tsinghua.edu.cn>
Wen-xiong Li (THU), Jun-cheng Chen(WZU), Xiaofeng Wang (THU), Kai Ye (YNAO), Ju-jia Zhang(YNAO), Chuan-jun Wang(YNAO), Jian-guo Wang(YNAO), Jin-ming Bai (YNAO), Jun Mo (THU), Kaixin Lu(YNAO) , Michael Coughlin (Caltech), Sarah Antier (APC), Tianrui Sun (PMO), Lei Hu (PMO), and Lifan Wang (TAMU/PMO) report on behalf of a larger collaboration:
Using the Lijiang 2.4-m telescope (LJT) at Yunnan Observatory, China, we observed the two candidates
ZTF19aarykkb and ZTF19aarzaod reported by the Zwicky Transient Facility (Kasliwal et al., GCN 24191)
as possible electromagnetic counterparts of the GW event S190425z (LIGO/Virgo Collaboration, GCN 24168).
Both have now been spectroscopically identified as type II SNe (Pavana et al., GCN 24200; Perley et al.,
GCN 24204; Buckley et al., GCN 24205; Izzo et al., GCN 24208; Wiersema et al., GCN 24209; Nicholl et al.,
GCN 24211). Multiple images were obtained with the LJT for these two SNe in g and r bands. Using the
Pan-STARRS Survey images as templates for image subtraction, the results of PSF photometry for them
are listed as
UT time: filter mag(error)
-------------------------------------------------------
ZTF19aarykkb:
2019-04-25T17:56:45 g 19.14+-0.07
2019-04-25T17:58:07 r 18.36+-0.06
2019-04-25T20:57:24 g 19.04+-0.06
2019-04-25T20:58:56 r 18.50+-0.05
-------------------------------------------------------
ZTF19aarzaod:
2019-04-25T21:06:56 r 19.93+-0.12
These magnitudes are consistent with previous reports (Hiramatsu et al., GCN 24194; Tan et al.,
GCN 24193; Burke et al. GCN 24206; Kilpatrick et al. 24212; Sun et al. GCN 24234), and also
consistent with the luminsoity of SNe II at a distance of about 110 Mpc after taking into the extinctions.
GCN Circular 24269
Subject
LIGO/Virgo S190425z - ePESSTO+ spectrum of candidate PS19qu
Date
2019-04-27T07:52:52Z (6 years ago)
From
Phil Short at Royal Observatory of Edinburgh <pshort@roe.ac.uk>
P. Short, M. Nicholl (Edinburgh), J. Anderson (ESO), T.-W. Chen (MPE), C. Inserra (Cardiff), O. Yaron (Weizmann), D. R. Young (QUB), C. Angus, M. Pursiainen, P. Wiseman (Southampton), S. Taubenberger (MPA), M. Gromadzki (Warsaw) on behalf of the ePESSTO+ collaboration
We obtained a spectrum of the transient PS19qu discovered by Pan-STARRS (Smith et al., GCN 24262) during follow-up of the gravitational wave trigger S190425z (GCN 24168) , under the advanced Public ESO Spectroscopic Survey for Transient Objects (ePESSTO+; see Smartt et al. 2015, A&A, 579, 40 http://www.pessto.org). The observations were performed on the ESO New Technology Telescope at La Silla with the EFOSC2 instrument.
The spectrum is host-galaxy dominated. It shows a star-forming galaxy at z=0.183, significantly further away than the peak of the distance posterior from the GW sky map (GCN 24168). At this redshift, the absolute magnitude implied by the Pan-STARRS detection is -18.9 mag.
[GCN OPS NOTE(27apr19): Per author's request, the "26c" in the Subject line and the "26z" in the first sentence
were changed to "25z".]
GCN Circular 24270
Subject
LIGO/Virgo S190425z: BOOTES-5/JGT observations of galaxies
Date
2019-04-27T08:08:12Z (6 years ago)
From
Alberto J. Castro-Tirado at IAA-CSIC <ajct@iaa.es>
Y.-D. Hu, X.-Y.Li, I. Carrasco, E. Fernandez-Garcia and A. J.
Castro-Tirado (IAA-CSIC), I. Carrasco, A. Castellon and C. Perez del
Pulgar (UMA), D. Hiriart and W. H. Lee (UNAM), S. Jeong and I. H. Park
(SKKU) and M. D. Caballero-Garcia (ASU-CAS, CZ) on behalf of a larger
collaboration, report:
Following the detection of the GW S190425z (GCN 24168), the 60cm
BOOTES-5/JGT robotic telescope at Observatorio Astronomico Nacional in
San Pedro Martir (Mexico) observed 63 galaxies selected from the GLADE
catalog in the LIGO/Virgo localization region (see D��lya and Raffai, GCN
24171). Data was gathered starting on Apr 25, 12:26 UT (4.1 hr post GW)
with a 20.5 limiting magnitude for each image (60s, clear filter). The
list of observed galaxies is given below. No transients are detected in
their vecinity. Further analysis is on its way.
We thank the staff at Observatorio Astronomico Nacional in San Pedro
Martir for their excellent support.
Obstime(UTC) Galaxy RA(J2000) DEC(J2000)
2019-04-25T12:26:51 2MASS16593507+0857289 16:59:35 +08:59:30
2019-04-25T12:25:24 2MASS16590113+0600559 16:59:01 +06:02:57
2019-04-25T12:23:55 2MASS16550989+0551321 16:55:10 +05:53:33
2019-04-25T12:22:31 2MASS16551814+0745247 16:55:18 +07:47:26
2019-04-25T12:21:05 2MASS16535916+0615267 16:53:59 +06:17:28
2019-04-25T12:19:34 2MASS16565156+0534093 16:56:51 +05:36:10
2019-04-25T12:18:06 2MASS16523061+0947018 16:52:30 +09:49:03
2019-04-25T12:16:38 2MASS16562595+0556173 16:56:26 +05:58:19
2019-04-25T12:15:10 2MASS16505118+0847019 16:50:51 +08:49:03
2019-04-25T12:13:40 2MASS16462248+0902154 16:46:22 +09:04:16
2019-04-25T11:29:03 2MASS17074548+0304469 17:07:45 +03:06:48
2019-04-25T11:27:39 2MASS17071043+0115389 17:07:10 +01:17:40
2019-04-25T11:26:15 2MASS17070140+0140412 17:07:01 +01:42:43
2019-04-25T11:24:50 2MASS17063227+0325482 17:06:32 +03:27:50
2019-04-25T11:23:24 2MASS17061937+0413572 17:06:19 +04:15:58
2019-04-25T11:21:58 2MASS17055844+0122534 17:05:58 +01:24:54
2019-04-25T11:20:28 2MASS17052220+0452370 17:05:22 +04:54:38
2019-04-25T11:19:02 2MASS17084532+0141056 17:08:45 +01:43:07
2019-04-25T11:17:36 2MASS17091821+0126260 17:09:18 +01:28:27
2019-04-25T11:16:11 2MASS17043225+0120477 17:04:32 +01:22:49
2019-04-25T11:14:44 2MASS17034317+0414546 17:03:43 +04:16:56
2019-04-25T11:13:15 2MASS17082207+0057506 17:08:22 +00:59:52
2019-04-25T11:11:50 2MASS17083335+0255486 17:08:33 +02:57:50
2019-04-25T11:10:23 2MASS17081604+0356386 17:08:16 +03:58:40
2019-04-25T11:08:58 2MASS17064993+0214392 17:06:50 +02:16:40
2019-04-25T11:07:32 2MASS17082534+0256016 17:08:25 +02:58:03
2019-04-25T11:06:09 HyperLEDA59425 17:00:52 +02:08:06
2019-04-25T11:04:46 2MASS17001211+0149023 17:00:12 +01:51:03
2019-04-25T11:03:19 2MASS17052314+0453080 17:05:23 +04:55:09
2019-04-25T11:01:53 2MASS17045647+0032286 17:04:56 +00:34:30
2019-04-25T11:00:27 2MASS17042272+0033347 17:04:23 +00:35:36
2019-04-25T10:59:02 2MASS17044072+0225487 17:04:40 +02:27:50
2019-04-25T10:57:34 2MASS17034446+0025416 17:03:44 +00:27:43
2019-04-25T10:56:08 2MASS17033766+0032426 17:03:37 +00:34:43
2019-04-25T10:54:41 2MASS17012629+0142014 17:01:26 +01:44:03
2019-04-25T10:53:14 2MASS17005511+0249298 17:00:55 +02:51:31
2019-04-25T10:51:47 2MASS16575622+0309255 16:57:56 +03:11:27
2019-04-25T10:50:20 2MASS16572411+0039141 16:57:24 +00:41:15
2019-04-25T10:48:52 2MASS17034447+0515245 17:03:44 +05:17:26
2019-04-25T10:47:27 2MASS16591074+0307545 16:59:10 +03:09:56
2019-04-25T10:46:03 2MASS16573413+0256065 16:57:34 +02:58:08
2019-04-25T10:44:28 2MASS16585516+0107243 16:58:55 +01:09:25
2019-04-25T10:42:48 2MASS16573844+0037045 16:57:38 +00:39:06
2019-04-25T10:41:22 2MASS17034514+0145216 17:03:45 +01:47:23
2019-04-25T10:39:54 2MASS16594619+0230353 16:59:46 +02:32:36
2019-04-25T10:38:31 2MASS17014185+0202344 17:01:42 +02:04:35
2019-04-25T10:37:05 2MASS16591559+0121545 16:59:15 +01:23:56
2019-04-25T10:35:39 2MASS16550578+0259381 16:55:06 +03:01:39
2019-04-25T10:34:15 2MASS17005227+0206066 17:00:52 +02:08:08
2019-04-25T10:32:48 NGC6230 16:50:47 +04:38:17
2019-04-25T10:31:19 2MASS16541350+0501271 16:54:13 +05:03:28
2019-04-25T10:29:51 2MASS16521538+0343210 16:52:15 +03:45:22
2019-04-25T10:28:23 2MASS16521412+0314088 16:52:14 +03:16:10
2019-04-25T10:26:45 2MASS16514686+0334557 16:51:47 +03:36:57
2019-04-25T10:25:19 2MASS16504997+0437178 16:50:50 +04:39:19
2019-04-25T10:23:52 2MASS16503422+0505350 16:50:34 +05:07:36
2019-04-25T10:22:23 2MASS16494530+0416395 16:49:45 +04:18:41
2019-04-25T10:20:18 2MASS16503128+0209319 16:50:52 +02:11:33
2019-04-25T10:12:45 UGC10104 15:57:28 +30:05:37
2019-04-25T10:09:54 HyperLEDA1843124 15:47:24 +28:43:32
2019-04-25T10:06:46 2MASS15585202+2608083 15:58:52 +26:10:09
2019-04-25T10:05:17 2MASS15562377+2549058 15:56:23 +25:51:07
2019-04-25T09:57:38 SDSSJ160952.75+223818.6 16:09:53 +22:38:19
GCN Circular 24274
Subject
LIGO/Virgo S190425z: Lulin Observations of Counterpart Search
Date
2019-04-27T09:17:29Z (6 years ago)
From
Albert Kong at NTHU <akhkong@gmail.com>
Han-Jie Tan (NCU), Po-Chieh Yu (NCU), Atharva Sunil Patil (NCU),
Chow-Choong Ngeow (NCU), Albert Kong (NTHU), Wing-Huen Ip (NCU)
On behalf of Global Relay of Observatories Watching Transients Happen
(GROWTH) collaborations
We report observations of 58 galaxies in 90% localization of the BNS merger
candidate, S190425z, detected by LIGO/Virgo (GCN #24168) using the Lulin
One-meter Telescope (LOT) in Taiwan. The observation started at 2019-04-25
14:11:07 UT, ~5.9 hours after the trigger. All images were taken in R-band
with 180 second exposure time. No significant transient can be identified
brighter than R~20 mag (AB). The galaxy coordinates are listed below.
We thank the staff in Lulin Observatory for helping the observations.
195.2782 +39.841
195.8646 +53.532
196.3275 +31.442
197.0104 +53.936
200.6963 +32.623
206.5110 +55.716
206.5117 +55.715
212.2203 +33.532
212.8712 +55.122
214.8233 +35.138
216.1732 +55.706
217.8031 +35.332
220.4162 +36.647
221.4388 +32.630
224.0184 +45.405
225.3241 +31.875
226.3790 +30.911
229.1854 +7.0222
32.0402 +43.007
233.1953 +40.223
233.4227 +28.145
234.6793 +30.671
236.9750 +25.730
237.0115 +25.439
237.4094 +42.034
238.7582 +41.578
239.0813 +24.747
239.8704 +39.828
243.6089 +35.109
243.9256 +19.638
244.1279 +35.708
244.5305 +21.066
244.8738 +18.480
245.7836 +19.006
246.1423 +21.195
246.4086 +16.455
247.4369 +40.812
247.5337 +14.904
248.3241 +35.342
248.5431 +19.634
249.0647 +10.843
249.3963 +11.733
250.0136 +15.883
250.1398 +8.988
251.5005 +7.189
251.5155 +9.283
252.3932 +9.783
252.4388 +4.278
252.4483 +4.932
252.7889 +7.677
253.2453 +2.401
253.2702 -16.291
253.7912 +5.859
254.1937 -1.962
254.3263 +0.570
254.3493 -1.797
254.3984 -1.796
256.2616 -4.596
GCN Circular 24285
Subject
LIGO/Virgo S190425z: CNEOST Optical Observations
Date
2019-04-27T15:02:40Z (6 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Bin Li, Hai-bin Zhao (PMO), Dong Xu, Zi-pei Zhu, Bang-yao Yu, Tian-meng
Zhang, Xu Zhou, Chen-zhou Cui, Hui-juan Wang (NAOC), Xue-feng Wu,
Zhi-ping Jin, Tian-rui Sun, Hao Lu, Ge-tu Zhaori, Ren-quan Hong,
Long-fei Hu (PMO), Xiao-feng Wang, Wen-xiong Li (THU), Li-fan Wang
(PMO/TAMU), Jin-zhong Liu (XAO), Ji-rong Mao, Jin-ming Bai (YNAO) report
on behalf of the CNEOST collaboration:
We conducted optical imaging observations for gravitational wave alert
with Chinese Near Earth Object Survey Telescope (CNEOST) at Xuyi
astronomical station in Jiangsu Province, China (32.75N, 118.47E). The
information of observations and preliminary results are listed below.
Alert: LIGO/Virgo S190425z (GCN 24168)
StartTime (UT): 2019-04-26T11:49:02.152
EndTime (UT): 2019-04-26T16:36:13.239
Skycover (Square Degree): 675.0
Telescope FoV (Square Degree): 9.0
# id CentRA(Degree) CentDEC(Degree) LimiteMag3\sigma 5\sigma 10\sigma
Filter
1 184.785507 26.824320 20.983 19.969 19.190
VR
2 192.873947 29.601379 20.944 19.900 19.114
VR
3 191.960449 32.390297 20.907 19.837 19.004
VR
4 183.234314 29.591774 21.019 19.959 19.177
VR
5 179.964020 21.201527 20.947 19.945 19.179
VR
6 187.898514 26.821241 20.979 19.949 19.173
VR
7 196.073746 29.603632 20.851 19.799 18.974
VR
8 189.684692 29.626089 20.875 19.864 19.036
VR
9 180.602478 23.990540 21.003 19.962 19.217
VR
10 184.785507 26.824320 20.983 19.969 19.190
VR
11 192.873947 29.601379 20.944 19.900 19.114
VR
12 191.960449 32.390297 20.907 19.837 19.004
VR
13 183.234314 29.591774 21.019 19.959 19.177
VR
14 198.608170 32.404903 21.028 19.933 19.087
VR
15 208.536697 32.404457 21.031 19.898 18.917
VR
16 215.425766 35.189808 20.952 19.912 18.869
VR
17 211.972580 35.169170 21.062 19.993 19.055
VR
18 201.739838 35.234352 21.097 20.013 19.149
VR
19 198.608170 32.404903 21.028 19.933 19.087
VR
20 208.536697 32.404457 21.031 19.898 18.917
VR
21 215.425766 35.189808 20.952 19.912 18.869
VR
22 211.972580 35.169170 21.062 19.993 19.055
VR
23 201.739838 35.234352 21.097 20.013 19.149
VR
24 201.873154 32.386822 21.000 19.912 19.094
VR
25 211.837280 32.391037 21.018 19.956 18.887
VR
26 216.216324 37.998722 21.074 19.972 18.897
VR
27 208.568130 35.197506 21.055 19.976 19.012
VR
28 198.301239 35.218636 21.127 20.040 19.123
VR
29 218.851593 35.218647 21.162 20.061 19.121
VR
30 222.244431 35.193432 21.146 20.100 19.256
VR
31 225.679306 35.158276 21.108 20.102 19.138
VR
32 229.114594 35.154079 21.109 20.069 19.083
VR
33 225.053543 29.585041 21.109 20.064 19.101
VR
34 218.484024 32.397865 21.157 20.051 19.053
VR
35 223.324417 38.002777 21.197 20.108 19.214
VR
36 225.081039 32.366611 21.100 20.031 19.062
VR
37 230.409027 37.977615 20.998 19.982 19.029
VR
38 228.267899 29.562998 21.050 20.002 19.011
VR
39 218.608292 29.590960 21.086 20.021 19.093
VR
40 219.784576 38.000137 21.168 20.108 19.188
VR
41 221.790970 32.360126 21.181 20.079 19.201
VR
42 226.883743 37.952568 21.151 20.092 19.148
VR
43 228.391403 32.370419 21.037 19.996 18.972
VR
44 221.833221 29.593536 21.120 20.102 19.196
VR
45 231.493652 29.561152 21.107 20.079 19.090
VR
46 233.963348 37.967670 21.103 20.118 19.248
VR
47 239.815979 40.776882 21.177 20.151 19.176
VR
48 235.000549 32.369446 21.087 20.096 19.212
VR
49 235.720306 23.978613 21.080 20.069 19.117
VR
50 231.493652 29.561152 21.107 20.079 19.090
VR
51 233.963348 37.967670 21.103 20.118 19.248
VR
52 239.815979 40.776882 21.177 20.151 19.176
VR
53 235.000549 32.369446 21.087 20.096 19.212
VR
54 235.720306 23.978613 21.080 20.069 19.117
VR
55 231.493652 29.561152 21.107 20.079 19.090
VR
56 233.963348 37.967670 21.103 20.118 19.248
VR
57 239.815979 40.776882 21.177 20.151 19.176
VR
58 235.000549 32.369446 21.087 20.096 19.212
VR
59 235.720306 23.978613 21.080 20.069 19.117
VR
60 238.067291 26.742233 21.075 20.070 19.136
VR
61 239.365143 35.179752 21.189 20.223 19.336
VR
62 244.608307 37.976181 21.162 20.188 19.205
VR
63 241.650742 32.340134 21.133 20.164 19.229
VR
64 241.823608 23.950287 21.047 20.079 19.143
VR
65 238.767471 23.968771 21.065 20.090 19.152
VR
66 238.319641 32.363117 21.178 20.198 19.319
VR
67 243.497925 40.747852 21.083 20.105 19.182
VR
68 242.779221 35.157001 21.160 20.204 19.243
VR
69 241.178314 26.761927 21.091 20.087 19.140
VR
70 236.980118 21.171730 21.104 20.122 19.199
VR
71 237.881577 29.548300 21.096 20.133 19.217
VR
72 241.073135 37.950817 21.136 20.129 19.225
VR
73 246.223633 35.124283 21.138 20.113 19.161
VR
74 241.141617 29.572805 21.075 20.098 19.182
VR
75 240.004684 21.128513 21.015 20.035 19.122
VR
Our vetting procedure based on image difference and machine learning
have identified some known sources (thus unrelated to the GW event) such as
OPEM-19fl = AT 2019dje
OPEM-19fj = SN 2019dek
OPEM-19fi = SN 2019dhc
OPEM-19fh = SN 2019dkx
OPEM-19fg = SN2019cdc
OPEM-19ff = AT 2019dku
OPEM-19fe = SN 2019dod
OPEM-19ex = AT 2019dzt
OPEM-19ev = AT 2018kud
OPEM-19eu = AT 2019dxm
OPEM-19eu = AT 2019dxm
OPEM-19en = AT 2019cya = ATLAS19ggy = ZTF19aaoyech
OPEM-19em = AT 2018ivk
No interesting transient can be reported here. Detailed data analysis is
still in progress and any interesting transient will be reported later.
GCN Circular 24295
Subject
LIGO/Virgo S190425z: Further confirmation for the classification of PS19qp/AT 2019ebq as a supernova
Date
2019-04-27T18:28:31Z (6 years ago)
From
Curtis McCully at Las Cumbres Observatory <cmccully@lco.global>
Curtis McCully (LCO), Daichi Hiramatsu (LCO/UCSB), D. Andrew Howell
(LCO/UCSB) Iair Arcavi (Tel Aviv University), Maria Drout (University of
Toronto), Jamison Burke (LCO/UCSB), Craig Peligrino (LCO/UCSB), Reinaldo de
Carvalho: (INPE), Francisco Fo��rster (Universidad de Chile), Ryan Foley
(UCSC), David Coulter (UCSC), Charles Kilpatrick (UCSC), David Sand (UA),
Stefano Valenti (UC Davis), Marcelle Soares-Santos (Brandeis), Sandro
Rembold (UFSM), Armin Rest (STSci), Daniel Kasen (UC Berkeley), Brian
Metzger (Columbia), Anthony Piro (Carnegie Obs.), Eliot Quataert (UC
Berkeley), Enrico Ramirez-Ruiz (UCSC), J. Craig Wheeler: (UT Austin), Franz
Bauer (Pontificia Universidad Catolica de Chile) Joshua Bloom (UC
Berkeley), Thomas Brink (UC Berkeley), Jeff Cooke (Swinburne University of
Technology), Alejandro Clocchiatti (Pontificia Universidad Catolica de
Chile), Alexei V. Filippenko (UC Berkeley), Wendy Freedman (University of
Chicago), Peter Garnavich (Notre Dame), Jorge Ernesto Horvath (Universidade
de Sao Paulo), Saurabh Jha (Rutgers), Robert Kirshner (Gordon and Betty
Moore Foundation), Kevin Krisciunas (Texas A&M), Huan Lin (FNAL), Barry
Madore (Carnegie Obs.), Martin Makler (Centro Brasileiro de Pesquisas
Fi��sicas), Xavier Prochaska (UCSC), Adam Riess (STSci), Riccardo Sturani
(UFRN), Nicholas Suntzeff (Texas A&M), Masaomi Tanaka (Tohoku University),
Douglas Tucker (FNAL), Jozsef Vinko (Konkoly Observatory), Lifan Wang
(Texas A&M), Jonathan Brown (Ohio State University), Carlos Contreras
(STSci), Chris D'Andrea (UPenn), Georgios Dimitriadis (UCSC), David Jones
(UCSC), Michael Lundquist (UA), Gautham Narayan (STSci), Felipe Olivares
(Universidad de Chile), Antonella Palmese (FNAL), Yen-Chen Pan: (NAOJ),
Daniel Scolnic (University of Chicago), Weikang Zheng (UC Berkeley),
Antonio Bernardo (Universidade de Sao Paulo), Azalee Bostroem (UC Davis),
Ariadna Murguia Berthier (UCSC), O��smar Rodri��guez (Universidad Nacional
Andres Bello), Ce��sar Rojas-Bravo (UCSC), Matthew Siebert (UCSC), and
Iruata�� Souza (Centro Brasileiro de Pesquisas)
We report spectroscopic observations of PS19qp/AT 2019ebq, the transient
reported by Pan-STARRS (Smith, et al., GCN 24210), using GMOS on Gemini
North at 2019-04-26 14:29:13. We combined 2x750s observations with a
central wavelength of 850nm.
We confirm the presence of broad P-cygni features identified by Morokuma et
al. (GCN 24230)
as the calcium IR triplet. We find that the spectrum is consistent with a
reddened (Nicholl et al., 24217) type Ib/c supernova in agreement with
Carini et al. (GCN 24252) and Jencson et al. (GCN 24233).
We thank the Gemini staff for their rapid response making these
observations possible.
GCN Circular 24296
Subject
LIGO/Virgo S190425z: Transient found in Swift/UVOT counterpart search
Date
2019-04-27T18:38:54Z (6 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
LIGO/Virgo S190425z: Transient found in Swift/UVOT counterpart search
A. A. Breeveld (MSSL-UCL), N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC), P. Brown (TAMU),
S. R. Oates (Uni. of Warwick), M. H. Siegel (PSU), M. de Pasquale (Uni. of Istanbul),
S. D. Barthelmy (NASA/GSFC), A. Y. Lien (GSFC/UMBC),
D. M. Palmer (LANL), T. Sakamoto (AGU), A. P. Beardmore (U. Leicester),
D. N. Burrows (PSU), S. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC),
G. Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA),
P. D'Avanzo (INAF-OAB), V. D'Elia(ASDC), S. Emery (UCL-MSSL),
P. A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU),
D. Hartmann (Clemson U.), J. A. Kennea (PSU), H. A. Krimm (NSF),
A. Melandri (INAF-OAB), B. Mingo (U. Leicester), J. A. Nousek (PSU),
P. T. O'Brien (U. Leicester), J. P. Osborne (U. Leicester), C. Pagani (U. Leicester),
K. L. Page (U.Leicester), M. Perri (ASDC),
J. L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU),
G. Tagliaferri (INAF-OAB), A. Tohuvavohu (PSU),
E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team:
We report a candidate transient found in the UVOT search results of the
LVC event S190425z (LIGO/VIRGO Collaboration GCN Circ. 24168).
On 2019-04-26 at 18:49:22 UT Swift UVOT took a 66.8 s exposure in the u band with
exposure ID uu577997367I (target ID 07016575) which shows a new source when compared with
archived DSS images. The new source is not listed in the Gaia DR1, 2MASS or GSC2.3
catalogs or Pan-STARRS and is not listed as a minor planet.
The position is:
RA = 255.5800 deg
Dec = -12.48562 deg
which is RA=17:02:19.2, Dec=-12:29:08.2 (J2000).
The magnitude using the UVOT photometric system (Breeveld et al. 2011, AIP
Conf. Proc. 1358, 373) is u=17.74 +/- 0.18 mag (Vega).
No source is found at this position in the XRT, with a 3-sigma upper limit of
5.8 x 10^-2 ct s^-1, which corresponds to a 0.3-10 keV observed flux of
2.5 x 10^-11 erg cm^-2 s^-1.
At this position, the distance estimate from the LALInference sky map has a mean
of 132 Mpc with a sigma of 35 Mpc.
There is a bright galaxy in the 2MPZ catalogue (Bilicki et al., 2014) 2MPZ
J17021587-1228210 at 68 arcsec (z = 0.022, D = 99 Mpc, abs K magnitude = 12.4),
which is 33 kpc away in projection. A second galaxy, 2MPZ J17020235-1229511 lies
250 arcsec away from the UVOT position. This galaxy has a distance of 106 Mpc in
the 2MPZ catalogue so the projected offset is 128 kpc. At the distance of these
galaxies, the absolute U magnitude would be -17.3, which is brighter than AT 2017gfo at
t ~ 2 days.
This circular is an official product of the Swift team.
GCN Circular 24301
Subject
LIGO/Virgo S190425z: Lulin observations of the Swift/UVOT transient
Date
2019-04-27T20:39:41Z (6 years ago)
From
Albert Kong at NTHU <akhkong@gmail.com>
Albert Kong (NTHU), Han-Jie Tan (NCU), Po-Chieh Yu (NCU), Chow-Choong Ngeow
(NCU), Wing-Huen Ip (NCU)
On behalf of Global Relay of Observatories Watching Transients Happen
(GROWTH) collaborations
We used the 1m telescope at the Lulin Observatory in Taiwan to obtain g-
and r-band images of the transient found by Swift/UVOT (GCN 24296). The
observations started at 2019-04-28 19:30 UT and the exposure time is 300s
for both filters. With a limiting magnitude of about 21.5 (AB) by comparing
to PS1 images, we do not detect the UVOT transient.
GCN Circular 24302
Subject
LIGO/Virgo S190425z: ZTF photometry of the UVOT transient candidate hours before discovery
Date
2019-04-27T21:06:42Z (6 years ago)
From
Igor Andreoni at Caltech <igor.andreoni@gmail.com>
Igor Andreoni (Caltech), S. Bradley Cenko (NASA GSFC), F. Masci (IPAC), M. Graham (Caltech)
On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations
We report pre-detection forced photometry upper limits for the Swift/UVOT transient candidate (Breeveld et al., GCN 24296) from recent observations with the Zwicky Transient Facility (ZTF). Forced photometry was performed on images processed through the ZTF reduction and image subtraction pipelines at IPAC (Masci et al. 2019).
------------------------------------
date (UT) | filter | maglim
------------------------------------
2019-04-25T10:05:01.746 | r | 20.51
2019-04-25T10:07:12.096 | g | 20.48
2019-04-25T11:26:44.153 | r | 20.47
2019-04-26T07:49:33.277 | g | 21.58
2019-04-26T09:36:47.686 | r | 20.42
------------------------------------
The candidate was detected with Swift/UVOT on 2019-04-26 at 18:49:22 UT (Breeveld et al., GCN 24296). Thus, if associated with the gravitational wave event, the ZTF non-detections may constrain the rise time and temperature during the rise of the transient.
The ZTF forced-photometry service was funded under the Heising-Simons Foundation grant #12540303 (PI: Graham). ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, UK and USyd, Australia. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949.
GCN Circular 24303
Subject
Correction to GCN Circular 24301: LIGO/Virgo S190425z: Lulin observations of the Swift/UVOT transient
Date
2019-04-27T21:07:09Z (6 years ago)
From
Albert Kong at NTHU <akhkong@gmail.com>
The start time in the previous circular is incorrect and has been corrected
here.
LIGO/Virgo S190425z: Lulin observations of the Swift/UVOT transient
Albert Kong (NTHU), Han-Jie Tan (NCU), Po-Chieh Yu (NCU), Chow-Choong
Ngeow (NCU), Wing-Huen Ip (NCU)
On behalf of Global Relay of Observatories Watching Transients
Happen (GROWTH) collaborations
We used the 1m telescope at the Lulin Observatory in Taiwan to obtain
g- and r-band images of the transient found by Swift/UVOT (GCN 24296).
The observations started at 2019-04-27 19:30 UT and the exposure time is
300s for both filters. With a limiting magnitude of about 21.5 (AB) by
comparing to PS1 images, we do not detect the UVOT transient.
GCN Circular 24304
Subject
LIGO/Virgo S190425z: GROWTH-India observations of the Swift/UVOT transient
Date
2019-04-27T21:24:40Z (6 years ago)
From
Varun Bhalerao at Indian Inst of Tech <varunb@iitb.ac.in>
G. Waratkar, H. Kumar, V. Bhalerao (IITB), J. Stanzin, G. C. Anupama (IIA) report on behalf of the Global Relay of Observatories Watching Transients Happen (GROWTH) collaboration:
We imaged the location of the Swift/UVOT transient candidate (Breeveld et al., GCN 24296) for the counterpart of LIGO/Virgo S190425z with the 0.7m GROWTH-India telescope. We obtained a 600s g band image starting at UT 2019-04-27T20:07:44, and a 600s r band image starting at UT 2019-04-27T19:42:49. The source was not detected in either of the images, down to a limiting magnitude of 21.0.
GCN Circular 24305
Subject
LIGO/Virgo S190425z: Swift/UVOT and XRT pre-images at the position of the potential Swift/UVOT counterpart
Date
2019-04-27T21:56:02Z (6 years ago)
From
Aaron Tohuvavohu at PSU/Swift <auc444@psu.edu>
Aaron Tohuvavohu (PSU), Phil Evans (U. Leicester), Mike Siegel (PSU),
Frank Marshall (NASA GSFC), Brad Cenko (NASA GSFC) and Jamie Kennea
(PSU) report on behalf of the Swift Gravitational Wave Galaxy Survey
(SGWGS) team
The position of the potential Swift/UVOT counterpart (Breeveld et
al. GCN. 24296) to the LIGO/Virgo S190425z trigger (LIGO/Virgo
Collaboration GCN. 24168) was imaged by the Neil Gehrels Swift
Observatory on 2018, October 21/22 UT with the Swift
Ultraviolet/Optical Telescope in the u and uvw1 filters for a total
1.2 ks of exposure as part of the Swift Gravitational Wave Galaxy
Survey (PI Tohuvavohu). Examining the image we do not detect any
source at the position of the counterpart candidate to a 5-sigma
limiting magnitude of ~21 mag in U-band, corresponding to ~ -14 mag
at the distance of the associated host galaxies (~100 Mpc). These
magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the event.
The Swift Gravitational Wave Galaxy Survey is a 5 Million second
pre-imaging survey of the ~14,000 most likely host galaxies for BNS
mergers within ~100 Mpc. It is performed in the u and uvw1 bands and
with XRT in the Photon Counting mode. It is currently ~43%
complete. When complete it will cover 41.2% of the integrated B-band
luminosity within 100 Mpc down to ~21 mag in u and uvw1 and
~5 �� 10 ���13 erg cm ���2 s ���1 in the X-rays (0.3 - 10 keV).
GCN Circular 24306
Subject
LIGO/Virgo S190425z: Pre-discovery NIR limits of the UVOT transient candidate from Gattini-IR
Date
2019-04-27T22:02:39Z (6 years ago)
From
Kishalay De at Caltech, GROWTH <kde@astro.caltech.edu>
K. De (Caltech), M. Hankins (Caltech), S. M. Adams (Caltech), M. M.
Kasliwal (Caltech), M. Coughlin (Caltech), I. Andreoni (Caltech), S.
Anand (Caltech), L. Singer (NASA GSFC), T. Ahumada (UMD), A. Moore
(ANU), J. Soon (ANU), M. Ashley (UNSW), T. Travouillon (ANU)
report on behalf of the Palomar Gattini-IR team and the larger GROWTH
(Global Relay of Observatories Watching Transients Happen)
collaboration
The Palomar Gattini-IR survey (Moore and Kasliwal 2019) observed the
location of the Swift UVOT counterpart candidate (GCN #24296) for the
BNS gravitational wave event S190425z (GCN #24168) on UT 2019-04-26
09:59 and UT 2019-04-25 at 10:54. Forced photometry on the images show
no source at the reported location down to a limiting magnitude of
15.2 AB mag in J band. The non-detections rule out bright infrared
emission from the source prior to the Swift detection.
GCN Circular 24307
Subject
LIGO/Virgo S190425z: No Optical Detection of the Swift/UVOT Transient with Las Cumbres Observatory
Date
2019-04-27T22:39:24Z (6 years ago)
From
Iair Arcavi at LCOGT <arcavi@gmail.com>
Iair Arcavi (Tel Aviv University), D. Andrew Howell (LCO/UCSB), Curtis
McCully (LCO), Daichi Hiramatsu (LCO/UCSB), Jamison Burke (LCO/UCSB), Craig
Pellegrino (LCO/UCSB) on behalf of the Las Cumbres GW Follow-up
Collaboration
We observed the field of the UVOT transient (Breeveld et al. GCN 24296)
with a Las Cumbres Observatory 1m telescope at the South African
Astronomical Observatory in the g and r bands starting at 2019-04-27 21:40
UT. We do not see the transient down to a g-band limiting magnitude of
roughly 21.8, and an r-band limiting magnitude of 21.5 (determined by
comparison to PS1 images).
GCN Circular 24309
Subject
LIGO/Virgo S190425z: ASAS-SN observations
Date
2019-04-27T23:03:16Z (6 years ago)
From
Benjamin Shappee at U. of Hawaii <shappee@hawaii.edu>
B. J. Shappee (IfA-Hawaii), C. S. Kochanek (OSU), K. Z. Stanek (OSU),
S. Holmbo (Aarhus), A. Franckowiak (DESY), T. W.-S. Holoien (Carnegie
Observatories),
J. L. Prieto (Diego Portales; MAS), Subo Dong (KIAA-PKU), T. A. Thompson
(OSU), J. F. Beacom (OSU)
ASAS-SN covered 10% of the probability region in the 1 hour preceding the
LIGO/Virgo Alert GCN #24168 of a BNS merger through normal operations.
Following, the LIGO/VIRGO alert optical follow-up was triggered with the
All-Sky Automated Survey for SuperNovae (ASAS-SN, Shappee et al. 2014;
Kochanek et al. 2017). ASAS-SN covered 67% of the probability region in
the 24 hours after the LIGO/VIRGO alert through a combination of normal
operations and triggered observations. The majority of the remaining
probability region was Sun constrained. We obtained 6 epochs on the
highest probability regions during that time. Candidates were scanned in
near real time. No obvious candidates were discovered. Given the lunation,
our depth was typically between g~18-18.5 mag.
Our coverage is shown here:
http://www.astronomy.ohio-state.edu/~assassin/LIGO/S190425z_coverage.png
We would like to thank Las Cumbres Observatory and its staff for their
continued support of ASAS-SN. ASAS-SN is funded in part by the Gordon and
Betty Moore Foundation through grant GBMF5490 to the Ohio State University,
NSF grant AST-1515927, the Mt. Cuba Astronomical Foundation, the Center for
Cosmology and AstroParticle Physics (CCAPP) at OSU, the Chinese Academy of
Sciences South America Center for Astronomy (CASSACA), and the Villum
Fonden (Denmark). For more information about the ASAS-SN project, see
http://www.astronomy.ohio-state.edu/asassn/index.shtml
GCN Circular 24311
Subject
LIGO/Virgo S190425z: Additional Candidates from the Zwicky Transient Facility
Date
2019-04-28T00:01:16Z (6 years ago)
From
Shreya Anand at GROWTH Caltech <sanand@caltech.edu>
Shreya Anand (Caltech), Mansi M. Kasliwal (Caltech), Michael W. Coughlin (Caltech), Tomas Ahumada (UMD), Daniel A. Perley (LJMU), Varun Bhalerao (IITB), Danny Goldstein (Caltech), �Leo P. Singer (NASA GSFC), Igor Andreoni (Caltech), Dmitry Duev (Caltech), S. Bradley Cenko (NASA GSFC), Eric C. Bellm (UW), Kishalay De (Caltech), Anna Ho (Caltech), Harsh Kumar (IITB), Gaurav Waratkar (IITB), Chris Copperwheat (LJMU), Virginia Cunningham (UMD), Shaon Ghosh (UWM), Ariel Goobar (OKC), David Kaplan (UWM), Jesper Sollerman (OKC), Joshua S. Bloom (UCB), M. Bulla (OKC), Nobuyuki Kawai (Tokyo Tech), Yoichi Yatsu (Tokyo Tech), Katsuhiro Murata (Tokyo Tech), Hidekazu Hanayama (IAO), Takashi Horiuchi (IAO), G. C. Anupama (IIA), G. Helou (IPAC)
On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations
We continued observations of the gravitational wave trigger S190425z (LVC et al. GCN 24168) with ZTF on UT 2019-04-26. We covered a total of 4950 sq deg in g-band and r-band with over 50% of the enclosed probability targeted based on the original sky map and 24% actual probability enclosed based on the new sky map. Each exposure on the second night was 90s, with a typical depth of 21 mag. See details in Kasliwal et al. GCN 24191 for additional details on data processing.
Objects with a spectroscopic host galaxy redshift higher than 0.1 were excluded and photometric redshifts, where available are noted below. Additional candidates with no detections prior to merger, inside the 90% localization area of the LALInference sky map are:
------------------------------------------------------------------------------------------------------------------
ZTF Name | RA (deg) | DEC (deg) ��| Filter | Mag ��| Magerr �| Notes
------------------------------------------------------------------------------------------------------------------
ZTF19aasckwd | 253.1643781 | �10.6022943 | r | 20.15 | 0.13 |
ZTF19aasfogv | 261.8430161 | -11.3338523 | g � | 20.53 | 0.18 | [hostless] [lowb]
ZTF19aasejil | 261.9458106 | ��1.6537207 | g | 20.53 | 0.14 | z~0.199 +/- 0.035 [nuc]
ZTF19aaryxjf | 254.5952784 | �-3.9847379 | g | 19.95 | 0.08 | z~0.083 +/- 0.015 [nuc]
ZTF19aascxux | 258.2933102 | �17.2938689 | g | 20.56 | 0.13 �
ZTF19aasdajo | 254.3550291 | �11.9961079 | g | 20.70 | 0.20 | z~0.292 +/- 0.067
ZTF19aasbamy | 231.2656676 | �24.9275799 | g | 20.66 | 0.15 | z~0.201 +/- 0.047
ZTF19aasckkq | 248.4131017 | �13.9101828 | g | 20.86 | 0.18 | z=0.0528 [specz]
ZTF19aarycuy | 244.0832042 | �21.7409392 | r | 20.07 | 0.15 | z~0.127 +/- 0.011 [nuc]
ZTF19aasbphu | 245.5831354 | �21.4081853 | r | 19.71 | 0.13 | z~0.0971 +/- 0.0292
�ZTF19aasbaui | 235.2496342 | �24.0816102 | g | 20.49 | 0.14 | z~0.216 +/- 0.052
�ZTF19aarxxwb | 288.6933231 | �-3.0075058 | g | 18.89 | 0.07 | [hostless] [lowb]
�ZTF19aashlts | 253.1875476 | -19.0941338 | r � | 19.95 | 0.11 | [lowb]
------------------------------------------------------------------------------------------------------------------
Notes:
[specz] : Spectroscopic redshift.
[hostless] : No discernable host galaxy.
[nuc] : Close to the host nucleus
[lowb] : Galactic latitude less than 20 degrees
Our most promising event is ZTF19aasckkq as it is -16.3 absolute mag and we encourage follow-up. We also encourage due diligence follow-up of ZTF19aasckwd and ZTF19aascxux. We caution these targets are somewhat fainter and our upper limits relatively less constraining on age. We also caution that we cannot rule out the supernova hypothesis.
Additional follow-up and analysis is ongoing.
ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, UK; TTU USA and USyd, Australia. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert filtering and follow-up co-ordination is being undertaken by the GROWTH marshal system (Kasliwal et al. 2019).
GCN Circular 24312
Subject
LIGO/Virgo S190425z: Potential host galaxy of UVOT candidate counterpart found in BLISS
Date
2019-04-28T00:13:42Z (6 years ago)
From
Antonella Palmese at Fermilab <palmese@fnal.gov>
A. Palmese (Fermilab), M. Soares-Santos (Brandeis U.), L. Santana-Silva (OV/UFRJ), A. Drlica-Wagner (Fermilab), K. Herner (Fermilab), R. Morgan (U Wisconsin-Madison)
We searched for previous observations at the position of the UVOT candidate (Breeveld et al. GCN Circ. 24296) in archival DECam data which we have compiled and processed as part of the Blanco Images of the Southern Sky (BLISS) project (PIs: Soares-Santos, Drlica-Wagner). The candidate was identified as part of the counterpart search for the LVC event S190425z (LIGO/VIRGO Collaboration GCN (Circ. 24168).
We find a faint object <1 arcsec away from the UVOT candidate. Visual inspection suggests it is a galaxy. Its AB magnitude is r=22.95+-0.096 (MAG_AUTO) at position (J2000):
RA 255.57996 deg
Dec -12.48536 deg
We suggest to observe this object in other bands or spectroscopically to assess its origin and redshift.
GCN Circular 24313
Subject
LIGO/Virgo S190425z: No Optical Detection of the Swift/UVOT Transient in ASAS-SN observations hours before and after discovery
Date
2019-04-28T00:26:54Z (6 years ago)
From
Benjamin Shappee at U. of Hawaii <shappee@hawaii.edu>
B. J. Shappee (IfA-Hawaii), C. S. Kochanek (OSU), K. Z. Stanek (OSU), S.
Holmbo (Aarhus), A. Franckowiak (DESY), T. W.-S. Holoien (Carnegie
Observatories), J. L. Prieto (Diego Portales; MAS), Subo Dong (KIAA-PKU),
T. A. Thompson (OSU), J. F. Beacom (OSU)
Swift reported a possible counterpart (Breeveld et al., GCN #24296) to
LIGO/Virgo
Alert GCN #24168 of a BNS merger. The reported detection was acquired
on 2019-04-26.784282
UT Swift UVOT u=17.74 +/- 0.18 mag (Vega). ZTF (Andreoni et al., GCN #24302
) reported non-detections 9 hours before the reported Swift observations.
ASAS-SN observations cover both 7 hours before and 12 hours after the
reported Swift transient with 3-sigma g-band limits deeper than the
reported u-band detection:
2019-04-25.4180376 >18.755
2019-04-26.4875420 >18.749
2019-04-27.3040667 >18.421
The transient Swift observed must have evolved on a short timescale or have
been very blue (u-g)~-1.
We would like to thank Las Cumbres Observatory and its staff for their
continued support of ASAS-SN. ASAS-SN is funded in part by the Gordon and
Betty Moore Foundation through grant GBMF5490 to the Ohio State University,
NSF grant AST-1515927, the Mt. Cuba Astronomical Foundation, the Center for
Cosmology and AstroParticle Physics (CCAPP) at OSU, the Chinese Academy of
Sciences South America Center for Astronomy (CASSACA), and the Villum
Fonden (Denmark). For more information about the ASAS-SN project, see
http://www.astronomy.ohio-state.edu/asassn/index.shtml.
GCN Circular 24314
Subject
LIGO/Virgo S190425z: Liverpool Telescope imaging of ZTF19aasckkq
Date
2019-04-28T00:46:18Z (6 years ago)
From
Daniel Perley at Liverpool JMU <d.a.perley@ljmu.ac.uk>
D. A. Perley, C. M. Copperwheat, and K. L. Taggart (LJMU) report on
behalf of the Global Relay of Observatories Watching Transients Happen
(GROWTH) collaboration:
We acquired a series of 60-second exposures of ZTF19aasckkq (Anand et
al., GCN 24311), an optical transient in the error region of LIGO/Virgo
S190425z (GCN 24168), using the IO:O imager on the 2m Liverpool
Telescope in the u, g, r, i, and z filters between 03:17:56 and 03:30:00
UT on 2019-04-27.
The transient is detected with the following magnitudes (measured after
image subtraction and calibrated relative to PS1):
JD magnitude
2458600.6384 g = 20.66 +/- 0.18
2458600.6395 r = 20.37 +/- 0.17
2458600.6406 i = 20.28 +/- 0.23
2458600.6416 z = 20.09 +/- 0.38
It is not detected in u-band. These suggest a moderately but not
extremely red transient and show no obvious evolution relative to the
ZTF imaging on 2019-04-26 (g = 20.86 +/- 0.18).
DisclaimerNone
GCN Circular 24315
Subject
LIGO/Virgo S190425z: SVOM/GWAC-F60A observations
Date
2019-04-28T00:48:58Z (6 years ago)
Edited On
2024-11-16T16:15:13Z (7 months ago)
From
Liping Xin at NAOC, SVOM <xlp@nao.cas.cn>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
L.P. Xin (NAOC), X.H. Han (NAOC), J.Y. Wei (NAOC), C. Wu (NAOC),
D. Turpin (NAOC), J.G. Ducoin (CNRS/LAL), D. Corre (CNRS/LAL),
L. Huang (NAOC), Y. Xu (NAOC), H.B. Cai (NAOC), J. Wang (NAOC),
X.M. Lu (NAOC), Y.L. Qiu (NAOC), J.S. Deng (NAOC), L. Jia (NAOC),
S.C. Zou (NAOC), S.F. Liu (NAOC), Q.C. Feng (NAOC), H.L. Li (NAOC),
D.W. Xu (NAOC), Y.J. Xiao (NAOC), W.L. Dong (NAOC), Y.T. Zheng (NAOC),
P. P. Zhang (NAOC), R.S. Zhang (NAOC), E.W. Liang (GXU),
X.G. Wang (GXU), Z.G. Dai (NJU), X.Y. Wang (NJU), Y.G. Yang (HBNU),
J.R. Mao (YNAO), B. Cordier (CEA/AIM), S. Basa (CNRS/LAM),
J.L. Atteia (UPS/IRAP), D. Götz (CEA/AIM), A. Claret (CEA/AIM),
N. Leroy (CNRS/LAL), C. Lachaud (CNRS/APC), S. Antier (CNRS/APC/CNES),
S.N. Zhang (IHEP), B.B. Wu (IHEP), report on behalf of the SVOM Ground Follow-up Group:
We observed the LIGO/Virgo trigger S190425z with GWAC-F60A.
Two 60cm GWAC-F60(A/B) are operated by Guangxi University and NAOC,
CAS, at Xinglong Observatory. China. They are equipped with Standard
Johnson filters and 2Kx2K Andor CCD (FOV~18x18 arcmin). GWAC-F60(A/B)
are used for galaxy-targeted observations. The galaxies are selected
from the GLADE catalog (Version 2.3, Dalya et al. 2018) in the probability
skymap of GW event. All these galaxies were observed in clear band.
The weather was not good during the observations.
The first image was taken ~6 hours after the event trigger. No credible
new source was detected in our pipeline. A total number of
80 galaxies were observed. The coordinates (J2000) of galaxies,
the observation time, the limit magnitude (3sigma) and telescopes
are listed below:
# Ra Dec start-obs(UTC) Limit (R) Telescope
246.40900 16.45500 2019-04-25T14:07:30.157 16.86 F60A
235.47600 28.13410 2019-04-25T12:26:20.678 20.16 F60A
236.94100 28.64190 2019-04-25T13:38:20.485 18.81 F60A
186.25200 28.55850 2019-04-25T12:14:11.215 20.25 F60A
241.23600 23.93290 2019-04-25T13:09:22.662 16.66 F60A
243.74100 21.93830 2019-04-25T13:49:55.528 14.15 F60A
246.11400 19.48260 2019-04-25T13:44:10.488 16.35 F60A
247.40100 15.65840 2019-04-25T14:03:29.676 17.11 F60A
252.98900 4.38356 2019-04-26T15:14:39.330 20.03 F60A
253.53600 -7.63537 2019-04-26T15:41:09.103 19.00 F60A
248.25700 22.79720 2019-04-26T16:18:33.855 18.88 F60A
246.40900 16.45500 2019-04-26T13:39:32.350 19.24 F60A
242.31500 25.71250 2019-04-26T13:29:26.576 18.96 F60A
101.82200 33.56730 2019-04-26T13:03:41.172 18.12 F60A
213.21400 35.71070 2019-04-26T19:31:21.044 15.55 F60A
252.26500 -17.64590 2019-04-26T18:17:23.676 15.12 F60A
213.61300 36.40440 2019-04-26T19:12:15.038 16.48 F60A
252.69500 4.60474 2019-04-26T15:10:41.648 18.50 F60A
253.24500 2.40099 2019-04-26T15:06:31.427 18.98 F60A
252.92700 -2.61525 2019-04-26T15:30:55.776 18.12 F60A
251.59400 9.03763 2019-04-26T14:23:38.733 17.37 F60A
188.92200 26.52300 2019-04-26T12:50:39.801 19.69 F60A
236.90100 26.06370 2019-04-26T12:40:17.254 19.40 F60A
252.71300 8.78387 2019-04-26T15:57:48.620 18.05 F60A
216.14600 35.27980 2019-04-26T13:12:20.095 18.89 F60A
256.23700 -1.53050 2019-04-26T19:27:31.002 14.74 F60A
239.01600 24.44800 2019-04-26T18:58:18.867 16.39 F60A
240.75100 27.01030 2019-04-26T12:36:02.920 18.67 F60A
246.06300 20.18360 2019-04-26T14:06:52.457 18.67 F60A
256.68100 -4.93311 2019-04-26T19:42:41.710 14.82 F60A
236.97500 25.72940 2019-04-26T16:10:06.932 18.87 F60A
189.55500 28.93690 2019-04-26T12:03:09.117 18.55 F60A
203.60500 34.69040 2019-04-26T12:59:12.069 19.63 F60A
240.68800 25.25220 2019-04-26T14:45:39.591 19.17 F60A
251.85200 -20.14170 2019-04-26T18:25:26.961 13.73 F60A
252.33700 -17.64450 2019-04-26T16:46:18.132 14.91 F60A
254.52400 -21.27410 2019-04-26T18:29:34.531 13.66 F60A
265.63300 0.21675 2019-04-26T18:54:30.920 13.77 F60A
252.72300 -15.00400 2019-04-26T16:22:46.980 16.61 F60A
217.50600 36.36090 2019-04-26T19:08:30.994 16.65 F60A
242.40600 28.05180 2019-04-26T14:31:48.522 19.80 F60A
258.11900 -9.12416 2019-04-26T16:26:50.153 16.71 F60A
218.40500 35.96650 2019-04-26T14:11:05.568 19.82 F60A
200.21300 43.96540 2019-04-26T12:26:20.960 19.19 F60A
243.14800 29.48450 2019-04-26T19:16:03.251 16.82 F60A
208.41000 36.13420 2019-04-26T13:33:42.807 19.49 F60A
249.86000 11.21050 2019-04-26T14:27:45.663 19.03 F60A
216.08600 36.46140 2019-04-26T12:16:57.909 19.57 F60A
190.43600 35.06290 2019-04-26T13:08:04.914 19.41 F60A
212.69800 35.91340 2019-04-26T12:08:27.646 19.09 F60A
243.14800 29.48480 2019-04-26T18:42:22.185 16.77 F60A
251.94600 -7.21269 2019-04-26T16:30:59.956 16.95 F60A
203.64600 34.77790 2019-04-26T19:19:52.570 15.29 F60A
253.27000 -16.29090 2019-04-26T18:13:21.035 15.42 F60A
221.59100 32.78010 2019-04-26T13:20:54.590 20.53 F60A
182.57600 26.43080 2019-04-26T14:19:29.899 20.04 F60A
243.14700 29.36490 2019-04-26T19:35:09.298 15.77 F60A
252.07700 6.31221 2019-04-26T14:53:56.092 18.74 F60A
254.78000 -5.74199 2019-04-26T15:45:20.977 17.63 F60A
253.60000 -9.88924 2019-04-26T16:01:51.545 16.91 F60A
193.51000 29.60370 2019-04-26T13:25:15.579 19.72 F60A
194.91500 53.34130 2019-04-26T12:12:42.478 20.34 F60A
242.27700 24.87030 2019-04-26T18:46:29.445 15.58 F60A
260.77200 12.69540 2019-04-26T16:05:56.399 17.81 F60A
256.25200 -1.54133 2019-04-26T19:38:57.637 14.77 F60A
253.72400 -16.95200 2019-04-26T16:50:26.458 14.38 F60A
205.41500 55.67070 2019-04-26T16:14:20.651 19.45 F60A
252.09000 6.22276 2019-04-26T14:49:46.057 18.45 F60A
196.48300 53.65920 2019-04-26T16:35:23.719 18.93 F60A
240.66900 37.35940 2019-04-26T12:21:33.662 19.43 F60A
252.38800 6.01625 2019-04-26T14:57:55.285 18.43 F60A
253.03200 -17.05380 2019-04-26T18:21:23.262 14.86 F60A
254.50500 -1.82269 2019-04-26T15:26:51.357 17.91 F60A
240.36900 22.42770 2019-04-26T14:15:09.801 19.36 F60A
232.92900 40.86490 2019-04-26T13:16:36.533 20.10 F60A
243.89800 19.45340 2019-04-26T18:50:43.803 15.42 F60A
255.21800 2.10185 2019-04-26T15:18:42.705 18.77 F60A
197.38900 53.49420 2019-04-26T12:31:38.012 20.40 F60A
250.01400 15.88340 2019-04-26T14:02:46.419 19.04 F60A
245.79700 16.93260 2019-04-26T13:58:39.077 19.32 F60A
This circular is citable.
GCN Circular 24318
Subject
LIGO/Virgo S190425z: No source found at UVOT source location at 6 hrs after LVC report
Date
2019-04-28T03:51:56Z (6 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
Myungshin Im (SNU), Joonho Kim (SNU), Gregory S. H. Paek (SNU), Chung-Uk
Lee (KASI), Seung-Lee Kim (KASI), Hyung Mok Lee (KASI), on behalf of a
larger collaboration
We checked the KMTNet image at the location of the UVOT transient
(Breeveld et al., GCN Circ. 24296). The image was taken at 2019-04-25
14:05:29 (UT) at the KMTNet Siding Spring Observatory station, about 6
hours after the GW detection (LVC collaboration, GCN Circ. 24168) and 28
hours before the reported UVOT detection. We do not find any transient at
the UVOT location down to the preliminary magnitude limit of R<21.5
(3-sigma, point source). We do find the reported faint host galaxy
candidate in our KMTNet data (Palmese et al., GCN Circ. 24312)
We thank the KMTNet operators for performing the observation.
GCN Circular 24319
Subject
LIGO/Virgo S190425z: NOT photometry of ZTF19aasckkq
Date
2019-04-28T04:18:11Z (6 years ago)
From
Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst <malesani@dark-cosmology.dk>
L. Izzo (HETH/IAA-CSIC), D. B. Malesani (DAWN/NBI and DARK/NBI), R.
Carini (INAF/OAR) report:
We observed the field of ZTF19aasckkq, reported by the Zwicky Transient
Facility (Anand et al., GCN 24311) to lie within the localization area
of the LIGO/Virgo trigger S190425z (GCN 24168). We used the Nordic
Optical Telescope (NOT) located in La Palma (Canary Islands, Spain) and
equipped with the AlFOSC camera.
We report the following magnitudes on the approximate date April 28.14
UT (2.8 days after the explosion of S190425z):
g = 20.63 +- 0.02
r = 20.33 +- 0.02
i = 20.29 +- 0.02
These magnitudes are calibrated against the Pan-STARRS survey; no
subtraction of the host galaxy was attempted, but the target is
relatively isolated and host contamination should not be a major
contribution. Our measurements are consistent with those reported by
Anand et al. (GCN 24311) on April 26 (unspecified time), as well as by
Perley et al. (GCN 24314) on April 27.14 UT.
The object seems therefore slowly variable, and less likely to be
associated with S190425z.
GCN Circular 24320
Subject
LIGO/Virgo S190425z: KPED Follow-Up of ZTF transients
Date
2019-04-28T05:08:34Z (6 years ago)
From
Tomas Ahumada at U. of Maryland <tahumada@astro.umd.edu>
Tomas Ahumada (UMD), Michael W. Coughlin (Caltech), Kai Staats
(Northwestern), Kevin Burdge (Caltech), Richard G. Dekany
<https://arxiv.org/search/astro-ph?searchtype=author&query=Dekany%2C+R+G>
(Caltech), Dmitry A. Duev
<https://arxiv.org/search/astro-ph?searchtype=author&query=Duev%2C+D+A>
(Caltech), Michael Feeney
<https://arxiv.org/search/astro-ph?searchtype=author&query=Feeney%2C+M>
(Caltech), S. R. Kulkarni
<https://arxiv.org/search/astro-ph?searchtype=author&query=Kulkarni%2C+S+R>
(Caltech), Reed Riddle
<https://arxiv.org/search/astro-ph?searchtype=author&query=Riddle%2C+R>
(Caltech) on behalf of the KPED team and the Global Relay of Observatories
Watching Transients Happen (GROWTH) collaboration.
We used the Kitt Peak EMCCD Demonstrator (KPED) on the Kitt Peak 84-inch
telescope (Coughlin et al 2019b) to obtain 300 s r-band images for ZTF
optical transients listed in Kasliwal et al. (GCN 24191) and Anand et al.
(GCN 24311) starting at 9:13:24 UT on 2019-04-27.
The measurement of ZTF19aasckkq is consistent with Perley et al. (GCN
24314) and we report upper limits for the rest of the transients.
Magnitudes are derived after calibrating against PS1:
ID JD RA DEC magnitude
ZTF19aasckkq 2458600.9291 248.413102 13.910183 r = 20.29 +- 0.18
ZTF19aaskbzh 2458600.9541 206.393046 69.329244 r > 19.65 +- 0.03
ZTF19aasejil 2458600.9837 261.945810 1.653720 r > 20.38 +- 0.34
ZTF19aasckkm 2458600.9248 247.302345 12.930679 r > 19.79 +- 0.18
More observations for this objects are scheduled.
The KPED team thanks the National Science Foundation, the National Optical
Astronomical Observatory and the Murty family for support in the building
and operation of KPED.
GCN Circular 24321
Subject
LIGO/Virgo S190425z: Spectroscopic observations of two ZTF candidates with SOAR
Date
2019-04-28T06:17:29Z (6 years ago)
From
Matt Nicholl at Royal Astronomical Soc. <mrn@roe.ac.uk>
M. Nicholl (Edinburgh), R. Cartier (CTIO), I. Pelisoli (Potsdam), E. Berger, P. Blanchard, T. Eftekhari, S. Gomez, G. Hosseinzadeh, A. Villar, P. Williams (Harvard), P. Cowperthwaite (Carnegie), K. Alexander, D. Coppejans, W. Fong, R. Margutti, G. Terreran (Northwestern), R. Chornock (Ohio), J. Braga (INPE), L. Chomiuk, J. Strader (MSU), C. Clemens, D. Reichart (UNC), M. Drout (Toronto), D. Sand, N. Smith (Arizona), D. Kasen (Berkeley), B. Metzger (Columbia)
We report spectroscopic observations with the 4m SOAR telescope and Goodman spectrograph, of two potential electromagnetic counterparts to the gravitational wave trigger S190425z (GCN 24168): ZTF19aasckkq and ZTF19aasckwd, reported by ZTF/GROWTH (Anand et al, GCN 24311).
These candidates were deemed to be the most likely counterparts as they are offset from bright galaxies and have low spectroscopic or photometric redshifts. ZTF19aasckkq has been detected in follow-up photometry by Perley et al. (GCN 24314), Malesani et al. (GCN 24319) and Ahumada et al. (GCN 24320).
SOAR classifications:
ZTF19aasckwd is a young Type Ia SN at z~0.15, consistent with the photometric redshift of the nearby galaxy.
ZTF19aasckkq also shows clear SN features in the spectrum. Using the code SNID (Blondin & Tonry, 2007) we find good matches to Type IIb SNe at z~0.05, consistent with the galaxy redshift.
GCN Circular 24324
Subject
LIGO/Virgo S190425z: 1.5m OSN and 10.4m imaging of the UVOT source field
Date
2019-04-28T07:28:53Z (6 years ago)
From
Alberto J. Castro-Tirado at IAA-CSIC <ajct@iaa.es>
Y.-D. Hu, A. J. Castro-Tirado, X.-Y. Li, A. Ayala, E. Fernandez-Garcia
and F. J. Aceituno (IAA-CSIC), R. Sanchez-Ramirez (INAF-IAPS), M. D.
Caballero-Garcia (ASU-CAS) and N. Castro-Rodriguez (GRANTECAN, IAC,
ULL), on behalf of a larger collaboration, report:
Following the detection of Swift/UVOT of a transient (Breeveld et al.,
GCN 24296) within the error area of the GW event S190425z (LIGO
Scientific Collaboration and the Virgo Collaboration, GCN 24168), we
observed the target with the 1.5m telescope at the Observatorio de
Sierra Nevada (Spain) in the R-band, starting on Apr 27, 03:44 UT. The
co-add of 3 frames (600s each) revealed no object down to 22.3 mag at
the position of the UVOT source. Deeper images were taken at the 10.4m
GTC telescope equipped with OSIRIS in La Palma (Spain) starting on Apr
27, 05:11 UT. The potential host galaxy reported by Palmese et al., GCN
24312) is detected in our 60s frames with r = 22.8+-0.2.
We acknowledge the excellent support from the GTC staff.
GCN Circular 24325
Subject
LIGO/Virgo S190425z: No i-band detection of the Swift/UVOT transient in SkyMapper observations
Date
2019-04-28T07:54:48Z (6 years ago)
From
Seo-Won Chang at SkyMapper <seowon.chang@anu.edu.au>
Seo-Won Chang (ANU/OzGrav), Christian Wolf (ANU/OzGrav), Christopher A. Onken (ANU), Lance Luvaul (ANU), Susan Scott (ANU/OzGrav) report on behalf of the SkyMapper Transient survey collaboration:
We checked the SkyMapper observations at the location of the Swift UVOT candidate (Breeveld et al. GCN 24296). These images were taken with the 1.35-m ANU SkyMapper telescope at Siding Spring Observatory about 6 hours after the GW detection in response to LIGO/Virgo GW trigger S190425z (LVC collaboration, GCN 24168). We do not see any transient down to an i-band (779/140 nm) magnitude of 20 (AB mag) at the two epochs: 2019-04-25 14:17:00 and 2019-04-25 14:25:53 UT. Our magnitude limits were obtained by calibrating with the zero-point from the SkyMapper Data Release 2 (Onken et al. 2019).
GCN Circular 24326
Subject
LIGO/Virgo S190425z: MASTER explanation of the nature of an optical flash detected by a Swift as a short flare on a fast-moving WISE brown
Date
2019-04-28T11:05:43Z (6 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, N.Tyurina, E. Gorbovskoy, V.Kornilov, D.Vlasenko,
V.Vladimirov, D.Zimnukhov, A.Kuznetsov, P.Balanutsa, I.Gorbunov, A.
Chasovnikov, V.Grinshpun, F.Balakin, A.Chasovnikov
(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C. Lopez, C.Francile, F. Podesta (Observatorio Astronomico Felix
Aguilar OAFA, San Juan National University),
H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio
ICATE,SJNU)
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres (The Instituto
de Astrofisica de Canarias),
D. Buckley (South African Astronomical Observatory),
O. Gress, N.M. Budnev, O.Ershova (Applied Physics Institute, Irkutsk State
University),
V. Yurkov, A. Gabovich, Yu. Sergienko, D. Kobcev (Blagoveschensk EducationState
University),
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov (Kislovodsk Solar Station
of the Pulkovo Observatory),
Global MASTER-Net (http://observ.pereplet.ru, Lipunov et al., 2010,
Advances in Astronomy, vol. 2010, 30L) started inspect of the
LIGO/Virgo S190425z errorbox (Singer et al. GCN 24168) 3133 sec after
trigger time at 2019-04-25 09:10:18 UT (Lipunov et al. GCN 24167).
MASTER-IAC observed Swift OT (Breeveld et al., GCN 24296) at 2019-04-26
01:45:59 with mlim=20.0, and at 2019-04-26 01:57:23 with mlim=20.0
during automatic inspect of GW190425.
There is optical transient with m_OT ~ 19.0 detected at both
images.
MASTER-OAFA observed these coordinates at 2019-04-26 05:24:35 during
automatic GW190425 inspection with unfiltered mlim=19.0. There is no OT
detection.
MASTER-SAAO observed this area at 2019-04-27 21:15:24 and at 2019-04-27
21:26:02 with mlim=21.0 and at 2019-04-26 04:01:55 with mlim=19.3 during
automatic GW190425 inspection . There is no OT detection.
All instrumental unfiltered magnitude is W = 0.2B + 0.8R with respect to
USNO B reference stars.
The object detected by Swift possibly connected with the blue flare on
fast moving cool AllWISE star (RA,DEC) = 255.5777822 -12.4869992 (2" per
yr!).
So this OT not connected with Gravitational Waves Event.
You can find below the community observations of the Swift OT
region:
Telescope Apr Limit OT Filt GCN
Zwicky 25.4 20.5 - R 24302
Zwicky 25.4 20.5 - g 24302
ASAS-SN 25.4 18.7 - g 24313
Gattini 25.5 15.2 - J 24306
Zwicky 25.5 20.5 - R 24302
KMTNet SSO 25.6 21.5 - R 24318
MASTER-IAC 26.1 20.0 19.0 W This
MASTER-OAFA 26.2 19.0 19.0 W This
Zwicky 26.3 20.5 - g 24302
Gattini 26.4 15.2 - J 24306
Zwicky 26.5 20.4 - R 24302
ASAS-SN 26.5 18.7 - g 24313
Swift 26.8 ? 17.7 U 24296
ASAS-SN 27.3 18.4 - g 24313
MASTER-SAAO 27.88 21.0 - W This
LCO SAAO 27.9 21.5 - R 24307
Lulin 28.8 21.5 - R 24301
These data do not contradict the hypothesis of a short (10-15 minutes
flash) on a red-brown dwarf.
The message may be cited.
GCN Circular 24328
Subject
LIGO/Virgo S190425z : IRSF/SIRIUS NIR photometric follow-up observation of the Swift/UVOT Transient
Date
2019-04-28T13:15:44Z (6 years ago)
From
Kumiko Morihana at Nagoya University <morihana@u.phys.nagoya-u.ac.jp>
K. Morihana (Nagoya U.), M. Jian (U. of Tokyo), T. Nagayama (Kagoshima
U.) on behalf of J-GEM collaboration
We carried out NIR photometric follow-up observation of Swift/UVOT
transient (Breeveld et al.,GCN 24296) of the GW event S190425z (GCN
24168) with the near-infrared (J, H, Ks) simultaneous imaging camera
SIRIUS attached to the IRSF (InfraRed Survey Facility) 1.4 m telescope
in Sutherland Observatory, South Africa.
The observation started on 2019-04-28 00:44:28 UT. The exposure time
on the source is 40 min. A very faint source (possibly noise) is seen
at the position of Swift/UVOT transient in the J-band image. The
simple aperture photometry returns J=20.2 mag (Vega system), but it is
quite unsure. The conservative upper limit magnitudes for the
JHKs-band images are 18.8 mag, 18.4 mag, and 16.9 mag (Vega system),
respectively.
GCN Circular 24334
Subject
LIGO/Virgo S190425z: VISTA K-band observations of the Swift/UVOT Transient
Date
2019-04-28T21:30:26Z (6 years ago)
From
Nial Tanvir at U.Leicester <nrt3@star.le.ac.uk>
N. R. Tanvir (U. Leicester), C. Gonzalez-Fernandez (IoA, U. Cambridge),
A. J. Levan (Radbound U.), D. B. Malesani (DAWN/NBI and DARK/NBI),
P. A. Evans (U. Leicester) report on behalf of the VINROUGE collaboration:
The location of the variable source reported in Swift/UVOT
observations (Breeveld et al., GCN 24296) appears in a field
imaged by the 4m VISTA telescope as part of our follow-up of the
binary neutron star merger S190425z (LVC collaboration, GCN 24168).
The observations were obtained on 2019-04-28 07:55 UT in the 2.15 um
Ks-filter. We find no significant flux at the transient location,
corresponding to a 2-sigma limiting magnitude of K(AB)~20.6.
The absence of a detection in these observations suggests that
either it has rapidly faded and/or is not very red in UV-nIR colours.
The faint constant source, close to the UVOT position, noted by
Palmese et al. (GCN 24312), is marginally visible in our imaging,
at about the 2-sigma level.
GCN Circular 24335
Subject
LIGO/Virgo S190425z: RATIR non-detection of the Swift/UVOT source
Date
2019-04-28T22:39:18Z (6 years ago)
From
Eleonora Troja at NASA/GSFC/UMD <eleonora@umd.edu>
Eleonora Troja (GSFC/UMD), Alan M. Watson (UNAM), Rosa L. Becerra (UNAM),
Nat Butler (ASU), Diego Gonzalez (UNAM), Alexander Kutyrev (GSFC/UMD),
William H. Lee (UNAM), Margarita Pereyra (UNAM), and
Tanner Wolfram (ASU) report:
We observed the location of the Swift/UVOT transient (Breeveld et al.,
GCN Circ. 24296) with the Reionization and Transients Infrared Camera
(RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
Astron��mico Nacional on Sierra San Pedro Martir from 2019/04 28.28 to
2019/04 28.49 UTC (approximately 3 d after the GW trigger), obtaining
a total of 1.92 hours exposure in the r and i bands and 1.21 hours
exposure in the Z, Y, J, and H bands.
For a source within the UVOT error circle, in comparison with the
USNO-B1 and 2MASS catalogs, we obtain the following upper limits (3-sigma):
g > 23.5
r > 23.4
i > 23.3
Z > 22.2
Y > 22.2
J > 21.8
H > 21.4
The nearby objected reported by Palmese et al. (GCN Circ. 24312) is
detected in our images at H~20.1 mag.
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
We thank the staff of the Observatorio Astronomico Nacional in San Pedro
Martir
GCN Circular 24337
Subject
LIGO/Virgo S190425z: DECam Observations of the UVOT Candidate Region
Date
2019-04-29T05:06:28Z (6 years ago)
From
Josh Bloom at UC Berkeley <jbloom@astron.berkeley.edu>
Joshua S. Bloom (UC Berkeley), Catherine Zucker (Harvard), Eddie Schlafly
(LBNL), Doug Finkbeiner (Harvard), Jorge Mart��nez-Palomera (UC Berkeley),
Daniel A. Goldstein (Caltech), and Igor Andreoni (Caltech) report:
"Starting at 2019-04-28 5:10 UTC, we observed the region of the UVOT
transient (Breeveld et al. GCN #24296) candidate counterpart of the
gravitational wave event S190425z (LIGO/VIRGO Collaboration, GCN #24168)
with the Victor M. Blanco 4m Telescope at Cerro Tololo Inter-American
Observatory, equipped with the Dark Energy Camera (DECam). We observed in
four bands (g for 6 minutes, r for 6 minutes, i for 8 minutes, z for 8
minutes).
Consistent with previous reports (Kong et al. GCN #24301, Arcavi et al. GCN
#24307, Im et al. GCN #24318, Shappee et al. GCN #24313, Hu et al. GCN
#24324, Chang et al. GCN #24325, Morihana et al. GCN #24328, Tanvir et al.
GCN #24334, Troja et al. GCN #24335), in 1.2 arcsec seeing, we find no
source at the reported position of the UVOT source, placing the following
upper limits, calibrated to PS1 photometry (Chambers et al. 2016,
arXiv:1612.05560C):
g > 24.0
r > 24.0
i > 23.7
z > 23.1
The nearby source noted in Palmese et al. (GCN #24312) at position
ra=17:02:19.19, dec=-12:29:07.3 is detected in r, i, z and not detected in
g. We report the following magnitudes for this source:
z = 21.50
i = 22.04
r = 23.03
g > 24.0
All detection magnitudes inhere a ~0.1 mag uncertainty currently. The
r-band detection is consistent with Palmese et al. (GCN #24312) and thus
does not appear to be variable between the two observations. We find no
evidence for any spatial extent beyond the stellar PSF. The photometric
measurements (albeit not corrected for the Galactic extinction along the
line of sight) suggest the source to be a M2-dwarf star (see West et al.,
2011).
The currently reported astrometric location of the bright UV transient is
not precisely consistent with the location of the source discussed above.
However, if they are indeed physically associated (through a refined
astrometric study, especially since the UVOT source appears trailed) a
consistent picture emerges: the UVOT detection was due to a flare from an
M2-dwarf star in our galaxy. We thus agree with the hypothesis advanced by
Lipunov et al. (GCN #24326) that the UVOT event is unrelated to GW
S190425z."
This message may be cited.
GCN Circular 24338
Subject
LIGO/Virgo S190425z: MASTER detection of the faint flare in SDSS Seyfert galaxy z = 0.09
Date
2019-04-29T07:37:07Z (6 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, N.Tyurina, E. Gorbovskoy, V.Kornilov, D.Vlasenko, V.Vladimirov,
D.Zimnukhov, A.Kuznetsov, P.Balanutsa, I.Gorbunov, A. Chasovnikov,
V.Grinshpun, F.Balakin, A.Chasovnikov (Lomonosov Moscow State University, SAI,
Physics Department),
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres (The
Instituto de Astrofisica de Canarias),
R. Podesta, C. Lopez, C.Francile, F. Podesta (Observatorio Astronomico Felix
Aguilar OAFA, San Juan National University),
H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio
ICATE,SJNU)
D. Buckley (South African Astronomical Observatory),
O. Gress, N.M. Budnev, O.Ershova (Applied Physics Institute, Irkutsk State
University),
V. Yurkov, A. Gabovich, Yu. Sergienko, D. Kobcev (Blagoveschensk EducationState
University),
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov (Kislovodsk Solar Station
of the Pulkovo Observatory),
Global MASTER-Net (http://observ.pereplet.ru, Lipunov et al., 2010, Advances in
Astronomy, vol. 2010, 30L) started inspect of the LIGO/Virgo S190425z
errorbox (Singer et al. GCN 24168) 3133 sec after trigger time at 2019-04-25
09:10:18 UT (Lipunov et al. GCN 24167).
After reviewing 25% of total probability, we found several possible
transients. The most interesting is the MASTER OT J155829.22+271714.6.
Most likely this flash is related to the activity of the galaxy nuclear.
Too large redshift s = 0.09 (distance ~380 Mpc) excludes OT from possible
candidates for a gravitational-wave event LIGO/Virgo S190425z.
MASTER OT J155829.22+271714.6 - Optical Flare in Active Seyfert Galaxy
MASTER-IAC (Teide Observatory, IAC, Tenerife, Spain) auto-detection system
discovered OT source at (RA, Dec) = 15h 58m 29.22s +27d 17m 14.63s
2019-04-25 23:42:39.4 UT.
The OT unfiltered magnitude is 18.4m (limit 19.7 m).
There is no minor planet at this place.
The discovery, referenceand differences images are available at
http://observ.pereplet.ru/images/MASTEROTJ155829.22+271714.6.jpg
The message may be cited.
GCN Circular 24343
Subject
LIGO/Virgo S190425z: KPED Follow-Up of ZTF transients
Date
2019-04-29T13:58:10Z (6 years ago)
From
Tomas Ahumada at U. of Maryland <tahumada@astro.umd.edu>
Tomas Ahumada (UMD), Michael W. Coughlin (Caltech), Kai Staats
(Northwestern), Kevin Burdge (Caltech), Richard G. Dekany (Caltech), Dmitry
A. Duev (Caltech), Michael Feeney (Caltech), S. R. Kulkarni (Caltech), Reed
Riddle (Caltech) on behalf of the KPED team and the Global Relay of
Observatories Watching Transients Happen (GROWTH) collaboration.
We used the Kitt Peak EMCCD Demonstrator (KPED) on the Kitt Peak 84-inch
telescope (Coughlin et al 2019b) to obtain 300 s r-band images for ZTF
optical transients listed in Kasliwal et al. (GCN 24191) and Anand et al.
(GCN 24311) starting at 3:56:56.876 UT on 2019-04-28.
The measurements of ZTF19aasckkq are consistent with Malesani et al. (GCN
24319) and Ahumada et al. (GCN 24320). The object ZTF19aasbphu shows a
slight decrease in the r magnitude (r~-0.3) with respect to Anand et al.
(GCN 24311)
We report upper limits for the rest of the transients. Magnitudes are
derived after calibrating against PS1:
ID JD RA DEC magnitude
ZTF19aasckkq 2458602.473900463 248.4131017 13.9101828 g = 20.7 +- 0.2
ZTF19aasckkq 2458601.7544584144 248.4131017 13.9101828 r = 20.2 +- 0.1
ZTF19aasckkq 2458602.474675926 248.4131017 13.9101828 r = 20.1 +- 0.1
ZTF19aasckkq 2458601.7452688077 248.4131017 13.9101828 I = 19.4 +- 0.3
ZTF19aasckkq 2458601.750166088 248.4131017 13.9101828 I = 19.4 +- 0.3
ZTF19aasbphu 2458601.7107427316 245.5831354 21.4081853 r = 19.47 +- 0.2
ZTF19aasejil 2458601.8664184026 261.9458106 1.6537207 r > 20.8
ZTF19aasbamy 2458601.664547176 231.2656676 24.9275799 r > 20.4
ZTF19aascxux 2458601.8588976967 258.2933102 17.2938689 r > 20.3
ZTF19aasfogv 2458601.8632696294 261.8430161 -11.3338523 r > 19.9
ZTF19aarycuy 2458602.4741666666 244.0832363 21.7409257 r > 19.9
More observations for this objects are scheduled.
The KPED team thanks the National Science Foundation, the Caltech Space
Innovation Council, the National Optical Astronomical Observatory and the
Murty family for support in the building and operation of KPED.
GCN Circular 24345
Subject
LIGO/Virgo S190425z: Gaia Photometric Alerts transient candidate
Date
2019-04-29T15:58:28Z (6 years ago)
From
Zuzanna Kostrzewa-Rutkowska at SRON <z.p.kostrzewa@sron.nl>
Z. Kostrzewa-Rutkowska (SRON/RU), S. Hodgkin, A. Delgado, D.L. Harrison, M.
van Leeuwen, G. Rixon, A. Yoldas (IoA Cambridge), D. Eappachen, P.G. Jonker
(SRON/RU) on behalf of Gaia Alerts team report the discovery of a transient
candidate within the probability skymap of S190425z (LIGO/VIRGO
Collaboration GCN Circ. 24168):
---------------------------------------------------------------------------
Name TNSid Date [TCB] RaDeg DecDeg AlertMag URL
---------------------------------------------------------------------------
Gaia19bpf AT2019egx 2019-04-28T17:04:25 8.95631 -35.89300 14.38
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19bpf/
---------------------------------------------------------------------------
Note: outburst of candidate CV ASASSN-14da
Acknowledgements: This work has made use of data from the European Space
Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by
the Gaia Data Processing and Analysis Consortium (DPAC,
https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC
has been provided by national institutions, in particular the institutions
participating in the Gaia Multilateral Agreement. ZKR, DE, and PGJ
acknowledge support from the European Research Council under ERC
Consolidator Grant agreement no 647208.
GCN Circular 24348
Subject
LIGO/Virgo S190425z: 1.3-m optical imaging of UVOT transient field
Date
2019-04-29T23:24:43Z (6 years ago)
From
Marc A. Murison at U.S.Naval Obs,Flagstaff <marc.nofs@gmail.com>
Marc A. Murison, U.S. Naval Observatory--Flagstaff Station (NOFS)
We imaged the position of the reported Swift/UVOT transient (Breeveld
et al., GCN Circ. 24296), potentially corresponding to LIGO/Virgo trigger
S190425z (LIGO/Virgo Collaboration, GCN Circ. 24168), with the NOFS
1.3-meter telescope. Nine 900-second exposures were taken in SDSS r (5)
and g (4). Examination and comparison to PS1 reveals no new sources
brighter than apparent SDSS r magnitude 22.3. Exposure times were
2019-04-28 08:44 to 11:12 UTC. Stacking images did not produce benefit
due to variable and worsening seeing.
GCN Circular 24354
Subject
LIGO/Virgo S190425z: Gaia Photometric Alerts transient candidates
Date
2019-04-30T15:16:32Z (6 years ago)
From
Zuzanna Kostrzewa-Rutkowska at SRON <z.p.kostrzewa@sron.nl>
Z. Kostrzewa-Rutkowska (SRON/RU), S. Hodgkin, A. Delgado, D.L. Harrison, M.
van Leeuwen, G. Rixon, A. Yoldas (IoA Cambridge), D. Eappachen, P.G. Jonker
(SRON/RU) on behalf of Gaia Alerts team report the discovery of transient
candidates within the probability skymap of S190425z (LIGO/VIRGO
Collaboration GCN 24168):
---------------------------------------------------------------------------
Name TNSid Date [TCB] RaDeg DecDeg AlertMag URL
---------------------------------------------------------------------------
Gaia19bpt AT2019ehz 2019-04-29T06:51:22 212.42448 55.49114 18.49
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19bpt/
Gaia19bps <http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19bpt/%0DGaia19bps>
AT2019ehy 2019-04-28T22:13:01 80.97925 -67.87885 15.78
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19bps/
Gaia19bpr AT2019ehx 2019-04-29T04:14:24 83.92087 -66.86490 14.19
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19bpr/
---------------------------------------------------------------------------
Notes:
Gaia19bpt - galaxy SDSS J140941.88+552928.1 brightens by 2 mag
Gaia19bps - blue source brightens by 0.4 mag
Gaia19bpr - HMXB RX J0535.6-6651 brightens by 1 mag
Acknowledgements: This work has made use of data from the European Space
Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by
the Gaia Data Processing and Analysis Consortium (DPAC,
https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC
has been provided by national institutions, in particular the institutions
participating in the Gaia Multilateral Agreement. ZKR, DE, and PGJ
acknowledge support from the European Research Council under ERC
Consolidator Grant agreement no 647208.
GCN Circular 24356
Subject
LIGO/Virgo S190425z: ZTF pre-detections of Gaia19bpt AT2019ehz
Date
2019-04-30T18:33:36Z (6 years ago)
From
Igor Andreoni at Caltech <igor.andreoni@gmail.com>
Igor Andreoni (Caltech), Eric Bellm (UW) report on behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations
We searched for Zwicky Transient Facility (ZTF) detections associated with Gaia19bpt AT2019ehz (Kostrzewa-Rutkowska et al., GCN 24354) in the archive of ZTF alerts. ��A source, dubbed ZTF19aarioci, was found varying at the location of Gaia19bpt.�� The source was first detected in ZTF data on 2019-04-21 (g ~ 19.8), with detections in the public surveys beginning on 2019-04-23.
The optical event was detected days before the gravitational wave trigger S190425z (LIGO and Virgo Collaboration, GCN 24168), therefore we exclude an association between Gaia19bpt AT2019ehz and S190425z.
ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, UK; TTU USA and USyd, Australia. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019).
GCN Circular 24358
Subject
LIGO/Virgo S190425z: Keck/MOSFIRE NIR spectroscopy of PS19qp (= AT 2019ebq)
Date
2019-04-30T20:50:59Z (6 years ago)
From
Georgios Dimitriadis at UCSC <gdimitri@ucsc.edu>
G. Dimitriadis, D. O. Jones, M. R. Siebert, J. S. Brown (UCSC),
I. Arcavi (Tel Aviv University), J. S. Bloom (UC Berkeley),
K. A. Bostroem (UC Davis), D. A. Coulter (UCSC), M. R. Drout (University of Toronto),
H. Ebeling (IfA-Hawaii), A. V. Filippenko (UC Berkeley), R. J. Foley (UCSC),
D. A. Howell (LCO/UCSB), T. Hung (UCSC), S. W. Jha (Rutgers), D. Kasen (UC Berkeley),
C. D. Kilpatrick (UCSC), A. L. Piro (Carnegie Obs.), J. X. Prochaska (UCSC),
E. Quataert (UC Berkeley), E. Ramirez-Ruiz (UCSC), A. G. Riess (STSci),
C. Rojas-Bravo (UCSC), D. J. Sand (UA), D. M. Scolnic (Duke), K. Siellez (UCSC),
S. Valenti (UC Davis) and W. Zheng (UC Berkeley).
We obtained near-IR spectroscopy of PS19qp (= AT 2019ebq) (GCN #24210), a proposed
counterpart to the gravitational wave event S190425z (GCN #24168), with the
Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE) on the Keck I telescope
on Mauna Kea, starting at UT 2019-04-26 14:32:11, aproximately 1.2 days after
the LIGO/Virgo alert.
Our spectrum covers the J-band (1.15-1.35 microns). Visual inspection of the spectrum
indicates it is consistent with Type Ic supernovae a few days prior to maximum light,
similar to previous spectroscopic classifications (GCN #24230, GCN #24233, GCN #24252).
We thank the staff of Keck observatory, especially Josh Walawender,
for facilitating this Target of Opportunity observation.
GCN Circular 24362
Subject
LIGO/Virgo S190425z: Gaia Photometric Alerts transient candidate
Date
2019-05-01T13:54:04Z (6 years ago)
From
Zuzanna Kostrzewa-Rutkowska at SRON <z.p.kostrzewa@sron.nl>
Z. Kostrzewa-Rutkowska (SRON/RU), S. Hodgkin, A. Delgado, D.L. Harrison, M.
van Leeuwen, G. Rixon, A. Yoldas (IoA Cambridge), D. Eappachen, P.G. Jonker
(SRON/RU) on behalf of Gaia Alerts team report the discovery of a transient
candidate within the probability skymap of S190425z (LIGO/VIRGO
Collaboration GCN 24168):
---------------------------------------------------------------------------
Name TNSid Date [TCB] RaDeg DecDeg AlertMag URL
---------------------------------------------------------------------------
Gaia19bpw AT2019eig 2019-04-29T15:15:23 9.92876 -31.99236 18.54
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19bpw/
---------------------------------------------------------------------------
Acknowledgements: This work has made use of data from the European Space
Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by
the Gaia Data Processing and Analysis Consortium (DPAC,
https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC
has been provided by national institutions, in particular the institutions
participating in the Gaia Multilateral Agreement. ZKR, DE, and PGJ
acknowledge support from the European Research Council under ERC
Consolidator Grant agreement no 647208.
GCN Circular 24366
Subject
LIGO/Virgo S190425z: Gaia Photometric Alerts transient candidates
Date
2019-05-02T13:22:02Z (6 years ago)
From
Zuzanna Kostrzewa-Rutkowska at SRON <z.p.kostrzewa@sron.nl>
Z. Kostrzewa-Rutkowska (SRON/RU), S. Hodgkin, A. Delgado, D.L. Harrison, M.
van Leeuwen, G. Rixon, A. Yoldas (IoA Cambridge), D. Eappachen, P.G. Jonker
(SRON/RU) on behalf of Gaia Alerts team report the discovery of transient
candidates within the probability skymap of S190425z (LIGO/VIRGO
Collaboration GCN 24168):
---------------------------------------------------------------------------
Name TNSid Date [TCB] RaDeg DecDeg AlertMag URL
---------------------------------------------------------------------------
Gaia19bqf AT2019eiu 2019-05-01T09:54:18 50.39901 -52.89803 18.81
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19bqf/
Gaia19bqe AT2019eit 2019-04-30T17:13:48 20.70267 -38.78741 18.76
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19bqe/
Gaia19bqd AT2019eis 2019-04-30T15:41:20 32.80392 -48.59636 18.68
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19bqd/
---------------------------------------------------------------------------
Acknowledgements: This work has made use of data from the European Space
Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by
the Gaia Data Processing and Analysis Consortium (DPAC,
https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC
has been provided by national institutions, in particular the institutions
participating in the Gaia Multilateral Agreement. ZKR, DE, and PGJ
acknowledge support from the European Research Council under ERC
Consolidator Grant agreement no 647208.
GCN Circular 24367
Subject
LIGO/Virgo S190425z: Konkoly imaging of target galaxies
Date
2019-05-02T13:57:30Z (6 years ago)
From
Jozsef Vinko at Konkoly Observatory <vinko@konkoly.hu>
J. Vinko, A. Bodi, L. Kriskovics, K. Sarneczky and A. Pal (Konkoly Observatory) report additional CCD imaging of potential host galaxies of S190425z targeted by the Hobby-Eberly Telescope VIRUS spectrograph (GCN #24175). CCD frames were taken with the 0.6/0.9m Schmidt telescope (FoV 70x70 arcmin^2, unfiltered, limiting mag ~21.5) and the 0.8m RC telescope (FoV 18x18 arcmin^2, g- and r-band, limiting mag r~20.4) between 2019-04-25.9 and 2019-04-26.0 UT. The frames were centered at the following positions:
241.236267 +23.932871 = 16:04:56.7 +23:55:58:33
247.400574 +15.65844 = 16:29:36.1 +15:39:03.38
253.245255 +2.400985 = 16:52:58.8 +02:24:03.06
254.505371 -1.822693 = 16:58:01.2 -01:49:20.17
254.780334 -5.741986 = 16:59:07.2 -05:44:31.14
The deepest unfiltered frames were compared to PS1 templates applying image subtraction.
No new transient source has been found on either frames down to the limiting magnitude of ~ 21.5 listed above.
GCN Circular 24369
Subject
LIGO/Virgo S190425z: Insight-HXMT observation and counterpart search
Date
2019-05-02T15:30:36Z (6 years ago)
From
Zhengwei Li at IHEP <lizw@ihep.ac.cn>
LIGO/Virgo S190425z: Insight-HXMT observation and counterpart search
J. Guan, Y. Nang, N. Sai, C, Wang, C. K. Li, J. Y. Liao, Y. Huang, Y. J. Yang, Z. W. Li, X. B. Li, G. Li, S. L. Xiong, L. Tao, C. Z.
+Liu, X. L. Cao, Y. Chen, A. M. Zhang, Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, M. Wu, Y. P. Xu, S. N.
+Zhang (IHEP), report on behalf of the Insight-HXMT team:
We performed small area scan survey of the LIGO localization region with Insight-HXMT after the LVC trigger S190425z (LVC et al. GCN
+24168). The observation started at 2019-4-25 16:28 UTC, about 8 hours after the trigger time. Four fields were visited, with
+overlaps, mapping 987.2 square degrees of the bayestar map 90% credible region and covering a sky region totalling of 20.4% of the
+LIGO localization likelihood. Each field was scanned twice and the total exposure time was 79.2 ks. No significant new source is
+found in the region in search of the Insight-HXMT raw light curves.
The survey also covered T2019ebq/PS19qp (Smith et al. GCN, 24210), a possible optical counterpart to S190425z, at 2019-04-26 02:12
+UTC (for 400s) and 2019-04-26 15:06 UTC (for 250s). We find no significant new X-ray sources in the data. The 5-sigma flux upper
+limits are obtained when fitting the light curves to the position of T2019ebq/PS19qp: 6.8 mCrab (HE���25-100 keV), 16.2 mCrab
+(ME���7-40 keV) and 5.2 mCrab (LE���1-6 keV). The flux upper limits for other positions in the scanned fields are about the same as
+quoted above.
Further analysis will be reported in the following circulars.
Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA)
+and the Chinese Academy of Sciences (CAS). More information could be found at: http://www.hxmt.org.
List of observed fields:
Start (UTC) RA and Dec (J2000) radius(degree)
2019/4/25 16:28 245 20 10
2019/4/25 19:38 252 12 10
2019/4/25 22:49 235 30 10
2019/4/26 02:00 255 0 10
2019/4/26 05:11 245 20 10
2019/4/26 08:22 252 12 10
2019/4/26 11:33 235 30 10
2019/4/26 14:44 255 0 10
--
Sincerely Yours,
Zhengwei Li,
Key Laboratory of Particle Astrophysics,
Institute of High Energy Physics,
Chinese Academy of Sciences, Beijing China
TEL:15210983070 E-mail:lizw@ihep.ac.cn
GCN Circular 24417
Subject
LIGO/Virgo S190425z: Konus-Wind observations
Date
2019-05-07T11:24:07Z (6 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
D. Svinkin, S. Golenetskii, R.Aptekar, D. Frederiks,
M. Ulanov, A. Tsvetkova, A. Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:
Konus-Wind (KW) was observing the whole sky at the time of the
LIGO/Virgo event S190425z (2019-04-25 08:18:05.017 UTC, hereafter T0;
LIGO/Virgo Collaboration GCN Circ. 24168).
No triggered KW event happened from ~6 days before and ~2 days
after T0. The closest waiting-mode event was ~0.5 days before T0.
Using waiting-mode data within the interval T0 +/- 100 s,
we found no significant (> 5 sigma) excess over the background
in both KW detectors on temporal scales from 2.944 s to 100 s.
We estimate an upper limit (90% conf.) on the 20 ��� 1500 keV fluence
to 9.0x10^-7 erg/cm^2 for a burst lasting less than 2.944 s and having a
typical KW short GRB spectrum (an exponentially cut off power law with
alpha =-0.5 and Ep=500 keV). For a typical long GRB spectrum (the Band
function with alpha=-1, beta=-2.5, and Ep=300 keV), the corresponding
limiting peak flux is 2.7x10^-7 erg/cm^2/s (20 ��� 1500 keV, 2.944 s scale).
All the quoted values are preliminary.
GCN Circular 24459
Subject
LIGO/Virgo S190425z: CAHA-GRANDMA Observation of the Swift UVOT Source
Date
2019-05-10T19:16:15Z (6 years ago)
From
Alexander Kann at IAA-CSIC <kann@iaa.es>
D. A. Kann (HETH/IAA-CSIC), C. Thoene (HETH/IAA-CSIC), C. Stachie
(Artemis), X. Zhang (THU), Z. Vidadi (Shao), M. Blazek (HETH/IAA-CSIC),
K. Bensch (HETH/IAA-CSIC), L. Izzo (HETH/IAA-CSIC), A. de Ugarte Postigo
(HETH/IAA-CSIC, DARK/NBI), S. Antier (APC), S. Basa (LAM), M. Boer
(Artemis), D. Corre (LAL), M. Coughlin (Caltech), D. Coward
(OzGrav-UWA), J.G. Ducoin (LAL), B. Gendre (OzGrav-UWA), P. Hello (LAL),
A. Klotz (IRAP), C. Lachaud (APC), N. Leroy (LAL), D. Turpin (NAOC), and
X. Wang (THU)
report on behalf of the HETH group and GRANDMA collaboration:
We observed the location of the Swift UVOT transient (Breeveld et al.,
GCN #24296) discovered in the error region of the aLIGO/Virgo Binary
Neutron Star merger event S190425z (Ligo Scientific Collaboration and
VIRGO Collaboration, GCN #24168, #24228), with
the 2.2m CAHA telescope and CAFOS. We obtained 3 x 240 s each in U/B and
6 x 120 s in V/Rc/Ic. The observations were performed on 2019-04-28 from
02:11:50 to 03:52:47 UT.
At the position (Palmese et al., GCN #24312) of the likely counterpart
(thought to be an M2 dwarf that had a powerful flare which UVOT
detected, Lipunov et al., GCN #24326; Bloom et al., GCN #24337), we
detect a source in Rc and Ic and derive the following upper limits and
magnitudes:
U > 22.9 mag;
B > 23.5 mag;
V > 23.5 mag;
Rc = 22.51 +/- 0.15 mag (depth Rc > 23.8 mag);
Ic = 21.53 +/- 0.15 mag (depth Ic > 22.9 mag).
Magnitudes are given in the AB system and were obtained vs. a comparison
star from PanSTARRS and the transformations of Lupton (2005).
Our detections are in reasonable agreement with other reports (Palmese
et al., GCN #24312; Bloom et al., GCN #24337; Hu et al., GCN #24324) and
indicate the source was quiescent during our observations.
GRANDMA (Global Rapid Advanced Network Devoted to the Multi-messenger
Addicts) is a network of robotic telescopes connected all over the world
with both photometry and spectrometry capabilities for Time-domain
Astronomy (https://grandma.lal.in2p3.fr/).
This message may be cited.
[GCN OPS NOTE(12jun19), The second reference in the first paragraph
was changed from "Breeveld et al., #24296" to
"Ligo Scientific Collaboration and VIRGO Collaboration, GCN #24168, #24228".]
GCN Circular 24673
Subject
LIGO/Virgo S190425z: No counterpart candidate in Zadko-GRANDMA observations.
Date
2019-05-28T22:21:03Z (6 years ago)
From
Bruce Gendre at UVI <bruce.gendre@gmail.com>
B. Gendre (OzGrav-UWA), C. Lachaud (APC), V. Aivazyan (Iliauni), K.
Barynova (Kyiv Uni), A. Burrel (OzGrav-UWA), B. Chabert (OzGrav-UWA), H.
Crisp (OzGrav-UWA), D.Coward (OzGrav-UWA), E. Howell (OzGrav-UWA), A. N.
Klotz (UPS), J. Moore (OzGrav-UWA), S. Antier (APC), S. Basa (LAM), M.
Boer (Artemis), D. Corre (LAL), M. Coughlin (Caltech), J.G. Ducoin
(LAL), P. Hello (LAL), A. Klotz (IRAP), N. Leroy (LAL), D. Turpin
(NAOC), X. Wang (THU),
report on behalf of the Zadko Telescope team and GRANDMA collaboration;
We performed tiled observations of LIGO/Virgo BNS event S190425z with
the Zadko telescope, using a clear filter.
The observation started on 04/25/19 14:56:19 UTC which corresponds
approximately to 6.65 hours after the GW trigger time. However, due to
hardware issues, the first images of interest were obtained the next day
(04/26/19, 14:19:00 UTC)
We performed the following observations in galaxy targeting mode:
R.A. DEC.
16:57:53 -01:56:51
16:57:38 -01:48:37
16:57:07 -01:52:10
16:04:51 +24:03:15
16:04:32 +23:55:05
We have not found any credible counterpart candidate, down to R ~ 16.
The Zadko team acknowledges support from the OzGrav Centre of Excellence
of the Australian Research Council. GRANDMA (Global Rapid Advanced
Network Devoted to the Multi-messenger Addicts) is a network of robotic
telescopes connected all over the world with both photometry and
spectrometry capabilities for Time-domain Astronomy
(https://grandma.lal.in2p3.fr/).
---
L'absence de virus dans ce courrier ��lectronique a ��t�� v��rifi��e par le logiciel antivirus Avast.
https://www.avast.com/antivirus
GCN Circular 24767
Subject
LIGO/Virgo S190425z: Swift UVOT - no new sources identified, and a summary of the Swift UVOT processing of GW triggers.
Date
2019-06-06T22:47:28Z (6 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL), A. A. Breeveld (MSSL-UCL), C. Gronwall (PSU),
F. E. Marshall (NASA/GSFC), S. R. Oates (Uni. of Warwick), M.J. Page
(UCL-MSSL),
M. de Pasquale (U Istambul), M. H. Siegel (PSU), A. D'Ai (INAF-IASFPA),
P. D'Avanzo (INAF-OAB), S. D. Barthelmy (NASA/GSFC), A. P. Beardmore (U.
Leicester),
D. N. Burrows (PSU), S. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC),
G. Cusumano (INAF-IASF PA), V. D'Elia(ASDC), P. A. Evans (U. Leicester),
P. Giommi (ASI), D. Hartmann (Clemson U.), J. A. Kennea (PSU),
H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), D. B. Malesani (DARK/NBI),
A. Melandri (INAF-OAB), J. A. Nousek (PSU), P. T. O'Brien (U. Leicester),
J. P. Osborne (U. Leicester), C. Pagani (U. Leicester), K. L. Page
(U.Leicester),
D.M. Palmer (LANL), M. Perri (ASDC), J. L. Racusin (NASA/GSFC), T. Sakamoto
(AGU),
B. Sbarufatti (INAF-OAB/PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu
(PSU),
and E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team:
The Neil Gehrels Swift Observatory UVOT and XRT instruments began pointed
galaxy-targeted followup of the LIGO/Virgo detected S190425z (LVC GCN.
24168)
at 2019-04-25 12:53 UT (T0+274 min), delayed due to a commanding gap.
The observations continued until 2019-04-26 20:15 UT, when they were aborted
to begin followup of S190426c (LVC GCN. 24237).
The UVOT points at the same sky area as the Swift XRT but with a slightly
smaller FOV (17'x17'). As announced in Tohuvavohu et al.
(GCN Circ. 24353 ), the Swift GW follow up can be seen at
http://www.swift.ac.uk/LVC/.
The Swift UVOT exposures of around 70s are usually in the u-band (central
wavelength 350nm) or a UV band when there are bright stars in the FOV. The
nominal exposure time varies depending on several factors like the slew
time.
The limiting magnitude can vary but typically is 18.6th magnitude.
Each field is automatically processed by detecting sources in the image,
matching them to several catalogs and screening the remaining sources to
remove artifacts. A check is made for any remaining candidates against the
Minor Planet Center list of solar system objects. Candidates are ranked for
further examination. In addition, for each galaxy detected in the UVOT image
which is in the GLADE catalog, a "postage stamp" image of a small region
around
the galaxy is produced as well as a comparison "postage stamp" from the
DSS to be used for manual inspection.
After the automated processing, potential candidates are all examined
manually.
This allows for the removal of image artifacts from our candidate lists
that
sometimes get flagged as potential sources. For S190425z the automated
processing
identified 21 source candidates which all, except for one, were either
image
artifacts or fast moving objects that passed the screening.
A further examination of the "postage stamps" with galaxies is then made as
effort allows. This is done mainly because the source-finding algorithm
has difficulty finding point sources in extended sources such as galaxies.
For the fields observed for S190425z, 2298 galaxy postage stamp images were
generated. No credible sources were found.
The candidate source reported in Breeveld et al. (GCN Circ. 24296) was
identified
initially by the automated processing, and is likely a very red flaring
object
(see also Lipunov et al. GCN Circ. 24326).