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LIGO/Virgo S200114f

GCN Circular 26731

Subject

LIGO/Virgo S200114f: Global MASTER-Net observations report

Date

2020-01-14T02:24:23Z (5 years ago)

From

Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev, O.Ershova 
(Irkutsk State University, API),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich, Yu. Sergienko 
(Blagoveschensk Educational State University)




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 S200114f errorbox  380 sec after trigger time at 2020-01-14 02:14:38 UT, with upper limit up to  18.2 mag. The observations began at zenith distance = 58 deg. The sun  altitude  is -26.5 deg. 

MASTER-Kislovodsk robotic telescope  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the LIGO/Virgo S200114f errorbox  381 sec after trigger time at 2020-01-14 02:14:39 UT, with upper limit up to  17.5 mag. The observations began at zenith distance = 69 deg. The sun  altitude  is -26.1 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=11224

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

     421 | 2020-01-14 02:14:38 |         MASTER-OAFA | (07h 21m 28.46s , +17d 44m 04.5s) |   C |    80 | 18.3 |        
     421 | 2020-01-14 02:14:39 |   MASTER-Kislovodsk | (07h 28m 48.40s , +16d 54m 16.5s) |   C |    80 | 17.4 |        
     421 | 2020-01-14 02:14:39 |   MASTER-Kislovodsk | (07h 20m 31.03s , +17d 20m 26.8s) |   C |    80 | 17.3 |        
     527 | 2020-01-14 02:16:19 |   MASTER-Kislovodsk | (07h 28m 45.30s , +16d 53m 07.0s) |   C |    90 | 17.5 |        
     527 | 2020-01-14 02:16:19 |   MASTER-Kislovodsk | (07h 20m 28.19s , +17d 19m 14.5s) |   C |    90 | 17.4 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.

GCN Circular 26732

Subject

LIGO/Virgo S200114f: Upper limits from IceCube neutrino searches

Date

2020-01-14T02:51:01Z (5 years ago)

From

Alex Pizzuto at ICECUBE/U of Wisconsin <pizzuto@wisc.edu>

IceCube Collaboration (http://icecube.wisc.edu/) reports:

Searches [1,2] for track-like muon neutrino events detected by IceCube
consistent with the sky localization of gravitational-wave candidate S200114f
 in a time range of 1000 seconds [3] centered on the alert event time
(2020-01-14 01:59:58.239 UTC to 2020-01-14 02:16:38.239 UTC) have been performed.

During this time period IceCube was collecting good quality data.
No significant track-like events are found in spatial coincidence of
S200114f calculated from the map circulated in the 2-Preliminary notice.

IceCube's sensitivity assuming an E^-2 spectrum (E^2 dN/dE) to neutrino
point sources within the locations spanned by the 90% spatial containment
of S200114f ranges from 0.029 to 0.583 GeV cm^-2 in a 1000 second
time window.

The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector
operating at the geographic South Pole, Antarctica. The IceCube realtime
alert point of contact can be reached at roc@icecube.wisc.edu<mailto:roc@icecube.wisc.edu>


[1] Bartos et al. arXiv:1810.11467Loading...
 
  (2018) and Countryman et al.arXiv:1901.05486Loading...
 
  (2019)
[2] PoS(ICRC2019)918 and Braun et al., Astroparticle Physics 29, 299 (2008)
[3] Baret et al., Astroparticle Physics 35, 1 (2011)

GCN Circular 26733

Subject

LIGO/Virgo S200114f: No counterpart candidates in HAWC observations

Date

2020-01-14T03:02:17Z (5 years ago)

From

Israel Martinez-Castellanos at UMD/HAWC <imc@umd.edu>

The HAWC Collaboration (https://www.hawc-observatory.org) reports:

The HAWC Collaboration performed a follow-up of the gravitational wave
trigger S200114f. At the time of the trigger the HAWC
local zenith was oriented towards (RA, Dec) = (47.5 deg, 18.9 deg).
11% 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 26.1 deg to 45 deg for the area searched in this
analysis. The 5sigma detection sensitivity to a 1s (100s) burst in the
80-800GeV energy range goes from 4.0e-6 erg/cm^2 to 1.1e-4 erg/cm^2
(2.0e-5 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.

GCN Circular 26734

Subject

LIGO/Virgo S200114f: Identification of a GW unmodeled transient candidate

Date

2020-01-14T03:24:22Z (5 years ago)

From

Deep Chatterjee at University of Wisconsin, Milwaukee <deep@uwm.edu>

The LIGO Scientific Collaboration and the Virgo Collaboration report:

We identified the unmodeled transient candidate S200114f during real-
time processing of data from LIGO Hanford Observatory (H1), LIGO
Livingston Observatory (L1), and Virgo Observatory (V1) at 2020-01-14
02:08:18.239 UTC (GPS time: 1263002916.239). The candidate was found
by the CWB [1] analysis pipeline with a version of the search called
�IMBH�. This name is not a classification of the candidate.

S200114f is an event of interest because its false alarm rate, as
estimated by the online analysis, is 1.2e-09 Hz, or about one in 25
years. The event's properties can be found at this URL:
https://gracedb.ligo.org/superevents/S200114f

Two sky maps are available at this time and can be retrieved from the
GraceDB event page:
 * cWB.fits.gz,1, an initial localization generated by cWB,
distributed via GCN notice about 5 minutes after the candidate event
time.
 * cWB.fits.gz,3 -- this is identical to cWB.fits.gz,1

The preferred sky map at this time is cWB.fits.gz,3. For the
cWB.fits.gz,3 sky map, the 90% credible region is 403 deg2.

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] Klimenko et al. PRD 93, 042004 (2016)

GCN Circular 26738

Subject

LIGO/Virgo S200114f: Coverage and upper limits from MAXI/GSC observations

Date

2020-01-14T04:34:49Z (5 years ago)

From

Hitoshi Negoro at Nihon U <negoro.hitoshi@nihon-u.ac.jp>

H. Negoro (Nihon U.), N. Kawai (Tokyo Tech), S. Sugita, M. Serino (AGU),
M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi, R. Takagi (Nihon U.),
T. Mihara, C. Guo, Y. Zhou, 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. Nakahira, Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, R. Shimomukai, M. Tominaga (JAXA),
Y. Ueda, A. Tanimoto, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.),
H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.),
M. Yamauchi, S. Iwahori, Y. Kurihara, K. Kurogi, K. Miike (Miyazaki U.),
T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU), M. Sugizaki (NAOC)
report on behalf of the MAXI team:

We examined MAXI/GSC all-sky X-ray images (2-20 keV)
after the LVC trigger S200114f at 2020-01-14 02:08:18.239 UTC (GCN 26734Loading...
 
 ).

At the trigger time of S200114f, the high-voltage of MAXI/GSC was off,
and it was turned on at T0+653 sec (+10.9 min).
The first one-orbit (92 min) scan observation with GSC after the event covered 100%
of the 90% credible region of the cWB skymap from 03:09:02 to 03:29:47 UTC (T0+3644 to T0+4889 sec).

No significant new source was found in the region in the one-orbit scan observation.
A typical 1-sigma averaged upper limit obtained in one scan observation
is 20 mCrab at 2-20 keV.

If you require information about X-ray flux by MAXI/GSC at specific coordinates,
please contact the submitter of this circular by email.

GCN Circular 26739

Subject

LIGO/Virgo S200114f: Upper limits from Fermi-GBM Observations

Date

2020-01-14T06:28:29Z (5 years ago)

From

Adam Goldstein at Fermi-GBM, USRA <adam.michael.goldstein@gmail.com>

A. Goldstein (USRA) reports on behalf of the Fermi-GBM Team and the
GBM-LIGO/Virgo group:

For S200114f and using the latest cWB skymap, Fermi-GBM was observing 100%
of the localization probability at event time.

There was no Fermi-GBM onboard trigger around the event time of the
LIGO/Virgo detection of GW trigger S200114f (GCN Circ. 26734Loading...
 
 ). 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.

We set upper limits on impulsive gamma-ray emission for the LVC
localization region at merger time. Using the representative soft, normal,
and hard GRB-like templates described in arXiv:1612.02395Loading...
 
 , we set the
following 3 sigma flux upper limits over 10-1000 keV, weighted by GW
localization probability (in units of 10^-7 erg/s/cm^2):

Timescale  soft     norm     hard
--------------------------------------
0.128 s:   5.3      8.8      16.
1.024 s:   1.7      2.6      5.8
8.192 s:   0.5      0.9      1.9

GCN Circular 26741

Subject

LIGO/Virgo S200114f: Candidates from the Zwicky Transient Facility

Date

2020-01-14T07:26:29Z (5 years ago)

From

Igor Andreoni at Caltech <igor.andreoni@gmail.com>

Igor Andreoni (Caltech), Harsh Kumar (IITB), Michael W. Coughlin (Caltech), Tomas Ahumada (UMD), Shreya Anand (Caltech), Leo Singer (NASA/GSFC), Mansi M. Kasliwal (Caltech), Varun Bhalerao (IITB), Kishalay De (Caltech), Danny Goldstein (Caltech), Ariel Goobar (OKC), Matthew Graham (Caltech), Erik Kool (OKC), Jesper Sollerman (OKC), Dmitry Duev (Caltech), Brad Cenko (NASA GSFC)
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 unmodeled gravitational wave trigger S200114f (LVC, GCN #26734Loading...
 
 ) with the Palomar 48-inch telescope equipped with the 47 square degree Zwicky Transient Facility camera (ZTF, Bellm et al. 2019, Graham et al. 2019).

The tiling was 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 beginning at 2020-01-14 03:39 UT, covering 77.7% of the integrated probability based on the cWB skymap (LVC, GCN #26734Loading...
 
 ). Each exposure was 300s, reaching a g-band median depth of 21.9 mag and r-band median depth of 21.6 mag. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC (Masci et al. 2019).

We queried the ZTF alert stream using the Kowalski infrastructure (Duev et al., 2019). We required at least 2 detections separated by at least 15 minutes to select against moving objects. Furthermore, we cross-matched our candidates with the Minor Planet Center to flag known asteroids. We require no spatially coincident ZTF alert to be issued before the detection time of S200114f. The candidates within the 95% probability contour of S200114f that passed the automatic selection criteria and human vetting are presented in the table below.

+--------------+----------+-------------+--------------+--------+------+----------+-------+-------+
|     Name     | IAU Name |      RA     |     Dec      | filter | mag  |   MJD    | b_Gal | Notes |
+--------------+----------+-------------+--------------+--------+------+----------+-------+-------+
| ZTF20aafdytz | AT2020vrLoading...
 
  | 07:34:06.13 | +16:46:00.51 |   g    | 20.9 | 58862.15 | 16.8  | (a)   |
| ZTF20aafdzkn | AT2020vsLoading...
 
  | 07:24:28.50 | +16:12:45.85 |   g    | 21.4 | 58862.15 | 14.4  |       |
| ZTF20aafeoka | AT2020vuLoading...
 
  | 07:16:47.14 | +10:37:18.97 |   g    | 21.6 | 58862.15 | 10.4  |       |
| ZTF20aafeadg | AT2020vwLoading...
 
  | 07:05:49.02 | +13:52:13.91 |   g    | 21.2 | 58862.15 | 9.4   | (b)   |
| ZTF20aafdyru | AT2020vgLoading...
 
  | 07:10:12.71 | +16:06:25.50 |   g    | 21.6 | 58862.15 | 11.3  | (c)   |
| ZTF20aafeaqk | AT2020vxLoading...
 
  | 07:08:43.68 | +14:38:15.44 |   g    | 21.2 | 58862.15 | 10.3  | (c)   |
| ZTF20aafemum | AT2020vtLoading...
 
  | 07:30:09.34 | +19:51:37.81 |   g    | 21.6 | 58862.15 | 17.1  | (d)   |
| ZTF20aafeewx | AT2020vyLoading...
 
  | 07:35:17.49 | +10:04:45.13 |   g    | 21.2 | 58862.16 | 14.2  |       |
| ZTF20aafegdf | AT2020vzLoading...
 
  | 07:34:32.29 | +08:47:16.85 |   g    | 21.0 | 58862.16 | 13.5  | (b)   |
| ZTF20aafedbk | AT2020waLoading...
 
  | 07:08:38.13 | +27:51:17.40 |   g    | 21.2 | 58862.16 | 15.7  | (b)   |
| ZTF20aafeccu | AT2020wcLoading...
 
  | 07:03:22.07 | +27:22:41.21 |   g    | 20.7 | 58862.16 | 14.5  | (d)   |
+--------------+----------+-------------+--------------+--------+------+----------+-------+-------+

(a) SDSS photoz = 0.193 +- 0.0502
(b) offset from possible host galaxy
(c) possible AGN based on WISE colors 
(d) possible host in Legacy Survey

We caution that the age of these candidates is not well constrained as our triggered ToO observations are deeper than the regular survey. We encourage follow-up.


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; IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, 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 coordination is being undertaken by the GROWTH marshal system (Kasliwal et al. 2019). Alert database searches are done with using the Kowalski infrastructure (Duev et al., 2019) and with AMPEL (Nordin et al. 2019).

GCN Circular 26742

Subject

LIGO/Virgo S200114f : no neutrino counterpart candidate in ANTARES search

Date

2020-01-14T07:37:09Z (5 years ago)

From

Thierry Pradier at ANTARES/IPHC/U of Strasbourg <tpradier@km3net.de>

M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (APC/Universite de Paris), M. Colomer (APC/Universite de Paris), D. Dornic (CPPM/CNRS), A. Kouchner (APC/Universite de Paris), T. Pradier (IPHC/Universite de Strasbourg) report on behalf of the ANTARES Collaboration:


Using on-line data from the ANTARES detector, we have performed a follow-up analysis of the
recently reported LIGO/Virgo S200114f event using the 90% contour of the Initial GW_SKYMAP probability
map provided by the GW interferometers (GCN26734Loading...
 
  <https://gcn.gsfc.nasa.gov/gcn3/26734.gcn3Loading...
 
 >). The ANTARES visibility at the time of the
alert, together with the 50% and 90% contours of the probability map are shown at http://antares.in2p3.fr/GW/S200114f_Initial.png <http://antares.in2p3.fr/GW/S200114f_Initial.png>.
Considering the location probability provided by the LIGO/Virgo collaborations, there is a
6.0% chance that the GW emitter was in the ANTARES **upgoing** field of view at the time of
the alert.

No up-going muon neutrino candidate events were recorded in the ANTARES sky during a
+/-500s time-window centered on the time 2020-01-14 02:08:18 and in the 90% contour of the S200114f
event. The expected number of atmospheric background events in the region visible by ANTARES is
3.33e-05 in the +/- 500s time window. An extended search during +/- 1 hour gives no
up-going muon neutrino coincidence. The expected number of atmospheric background events in the
region visible by ANTARES is 2.39e-04 in this larger time window.

ANTARES is the largest undersea neutrino detector, installed in the Mediterranean Sea, and it is
primarily sensitive to neutrinos in the TeV-PeV  energy range. At 10 TeV, the median angular
resolution for muon neutrinos is about 0.5 degrees. In the range 1-100 TeV ANTARES has a
competitive sensitivity to this position in the sky.

GCN Circular 26743

Subject

LIGO/Virgo S200114f: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation

Date

2020-01-14T08:13:41Z (5 years ago)

From

Alexis Coleiro at APC/U. Paris Diderot <coleiro@apc.in2p3.fr>

Alexis Coleiro (APC, France), Carlo Ferrigno (ISDC/UniGE, Switzerland),
V. Savchenko (ISDC/UniGE, Switzerland),
J. Rodi (IAPS-Roma, Italy),
S. Mereghetti (INAF IASF-Milano, Italy)

on behalf of the INTEGRAL multi-messenger collaboration:
https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration

Using combination of INTEGRAL all-sky detectors (following [1]):
SPI/ACS, IBIS/Veto, and IBIS we have performed a search for a prompt
gamma-ray counterpart of S200114f (GCN 26734Loading...
 
 ).

At the time of the event (2020-01-14 02:08:18 UTC, hereafter T0),
INTEGRAL was operating in nominal mode. The peak of the event
localization probability was at an angle of 91 deg with respect to the
spacecraft pointing axis. This orientation implies strongly suppressed
(2.2% of optimal) response of ISGRI, strongly suppressed (9% of
optimal) response of IBIS/Veto, and somewhat suppressed (57% of
optimal) response of SPI-ACS.

The background within +/-300 seconds around the event was rather
stable (excess variance 1.2).

We have performed a search for any impulsive events in INTEGRAL SPI-
ACS (as described in [2]), IBIS, and IBIS/Veto data.

We do not detect any significant counterparts and estimate a 3-sigma
upper limit on the 75-2000 keV fluence of 3.1e-07 erg/cm^2 (within the
50% probability containment region of the source localization) for a
burst lasting less than 1 s with a characteristic short GRB spectrum
(an exponentially cut off power law with alpha=-0.5 and Ep=600 keV)
occurring at any time in the interval within 300 s around T0. For a
typical long GRB spectrum (Band function with alpha=-1, beta=-2.5, and
Ep=300 keV), the derived peak flux upper limit is ~2.5e-07 (8.8e-08)
erg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range.

We report for completeness and in order of FAP, all excesses
identified in the search region. We find:

T-T0 | scale | S/N | flux ( x 1e-06 erg/cm2/s) | FAP  
-20.5 | 0.85 | 4.3 | 4.62 +/- 0.994 +/- 1.13 | 0.0604 
-32.7 | 1.25 | 3.2 | 2.83 +/- 0.817 +/- 0.696 | 0.336 
57.5 | 1 | 3.3 | 3.37 +/- 0.914 +/- 0.827 | 0.579 
-149 | 0.85 | 3.7 | 4.1 +/- 0.993 +/- 1.01 | 0.803 
-154 | 1.6 | 3.4 | 2.66 +/- 0.722 +/- 0.652 | 0.912

Note that FAP estimates (especially at timescales above 2s) may be
possibly further affected by enhanced non-stationary local background
noise. This list excludes any excesses for which FAP is close to
unity.

All results quoted are preliminary.

This circular is an official product of the INTEGRAL Multi-Messenger
team.

[1] Savchenko et al. 2017, A&A 603, A46 [2] Savchenko et al. 2012, A&A
541A, 122S

GCN Circular 26744

Subject

LIGO/Virgo S200114f: not observable by AGILE at the event time

Date

2020-01-14T09:38:42Z (5 years ago)

From

Fabrizio Lucarelli at SSDC/INAF-OAR <fabrizio.lucarelli@ssdc.asi.it>

F.Lucarelli, C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and
Univ. Roma Tor Vergata), C.Casentini, M.Cardillo, G. Piano, A.Ursi (INAF/IAPS),
F. Verrecchia (SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti, 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 S200114f at T0 = 2020-01-14
02:08:18.2393 (UT), a preliminary analysis of the AGILE minicalorimeter (MCAL)
and GRID data found no acquisitions around T0, due to a complete Earth
occultation of the S200114f 90% c.l. localization region.

Additional analysis of AGILE data is in progress.

GCN Circular 26745

Subject

LIGO/Virgo S200114f: No counterpart candidates in Fermi-LAT observations

Date

2020-01-14T11:02:00Z (5 years ago)

From

Lorenzo Scotton at CNRS/IN2P3/LUPM <lorenzoscotton@live.it>

L. Scotton (CNRS/IN2P3/LUPM), M. Crnogorcevic (Univ. of Maryland & 
NASA/GSFC), M. Axelsson (KTH & Stockholm Univ.) and F. Longo (University 
and INFN, Trieste) report on behalf of the Fermi-LAT Collaboration:

We have searched data collected by the Fermi Large Area Telescope (LAT) 
on Jan 14, 2020,��for possible high-energy (E > 100 MeV) gamma-ray 
emission in��spatial/temporal��coincidence with the LIGO/Virgo trigger 
S200114f (GCN 26734Loading...
 
 ).

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 
time, and��"cumulative��coverage" as the integral of the instantaneous 
coverage over time.��Fermi-LAT had��an instantaneous coverage of ~87% of 
the LIGO probability at the��time of the trigger��(T0 = 
2020-01-1402:08:18.230UTC), and reached 100%��cumulative coverage��after 
~4.2 ks.

We performed a search for a transient counterpart within the observed 
region of the 90% contour of��LIGO map in a fixed time window from T0 to 
T0 + 10 ks.��No significant new sources��are found.

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 
1 GeV��for this search vary��between 2e-10 and 2e-08 [erg/cm^2/s].

The Fermi-LAT point of contact for this event is Milena Crnogorcevic 
(mcrnogor@astro.umd.edu).

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 26748

Subject

LIGO/Virgo S200114f: no counterpart candidates in the Swift/BAT observations

Date

2020-01-14T16:13:47Z (5 years ago)

From

Amy Lien at GSFC <amy.y.lien@nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (NASA/GSFC),
A. Y. Lien (GSFC/UMBC), T. Sakamoto (AGU),
A. P. Beardmore (U. Leicester), M. G. Bernardini (INAF-OAB),
A. A. Breeveld (MSSL-UCL), 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 (ASI-ASDC), S. Emery (UCL-MSSL),
P. A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU),
D. Hartmann (Clemson U.), J. A. Kennea (PSU),
N. Klingler (PSU), H. A. Krimm (NSF),
N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), J. A. Nousek (PSU),
S. R. Oates (U. of Birmingham), P. T. O'Brien (U. Leicester),
J. P. Osborne (U. Leicester), C. Pagani (U. Leicester),
K. L. Page (U.Leicester), M. J. Page (UCL-MSSL), M. Perri (ASDC),
J. L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU),
M. H. Siegel (PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (U. Toronto),
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 S200114f (LIGO/VIRGO Collaboration GCN Circ. 26734Loading...
 
 ),
where T0 is the LVC trigger time (2020-01-14T02:08:18.239 UTC).

The center of the BAT field of view (FOV) at T0 is
RA = 83.757 deg,
DEC = 9.589 deg,
and the roll angle is 254.150 deg.
The BAT FOV (>10% partial coding) covers 97.71% of the integrated
LVC localization probability. Note that the sensitivity in the BAT FOV
changes with the partial coding fraction. Please see the BAT FOV figure
in the summary page (link below) for the specific location of the LVC
region relative to the BAT FOV.

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 ~ 8.58 x 10^-8 erg/s/cm^2.
Assuming a luminosity of ~ 2 x 10^47 erg/s (similar to GW170817)
and an average Epeak of ~ 400 keV for short GRBs (Bhat et al. 2016),
this flux upper limit corresponds to a distance of ~ 77.58 Mpc.

Event data are available from T0-44.53 s to T0+45.57 s.
No significant detections (above our typical
image threshold of ~ 6.5 to 7 sigma) are found in the 15-350 keV images
created using intervals of T0-0.1 to T0+0.1 s, T0-2 s to T0+8 s, and the
whole event data range.

BAT retains decreased, but significant, sensitivity to rate increases for
gamma-ray events outside of its FOV. About 2.29% 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 than those
within the FOV.

The results of the BAT analysis are available at
https://swift.gsfc.nasa.gov/results/BATbursts/team_web/S200114f/web/source_public.html

GCN Circular 26749

Subject

LIGO/Virgo S200114f: upper limits from AGILE-GRID observations

Date

2020-01-14T17:06:46Z (5 years ago)

From

Fabrizio Lucarelli at SSDC/INAF-OAR <fabrizio.lucarelli@ssdc.asi.it>

F. Lucarelli, C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and
Univ. Roma Tor Vergata), C. Casentini, M. Cardillo, G. Piano, A.Ursi (INAF/IAPS),
F. Verrecchia (SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti, 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 S200114f at T0 = 2020-01-14
02:08:18.239 (UT), an analysis of the AGILE exposure at T0 showed that the
GW localization region (LR) was occulted by Earth (GCN #26744Loading...
 
 ).

We performed an analysis of the GRID data over time intervals before and
after T0, when good exposures of the S200114f 90% c.l. LR were available.

No candidate gamma-ray transient was detected.

The following preliminary GRID values of 3-sigma upper limits (ULs) in
the 50 MeV - 10 GeV energy band are obtained over different time intervals:

- (T0 + 600 s ; T0 + 700 s): from 4.0e-08 to 4.1e-08 erg cm^-2 s^-1, with an
exposure of about 14% of the S200114f 90% c.l. LR;

- (T0 - 6 hrs; T0 + 6 hrs): from 7.3e-10 to 5.0e-09 erg cm^-2 s^-1, and

- (T0 - 3 days; T0 + 6 hrs): from 7.6e-11 to 5.3e-10 erg cm^-2 s^-1,

both with an exposure of about 53% of the S200114f 90% c.l. LR;

These measurements were obtained with AGILE observing a large portion of
the sky in spinning mode.

GCN Circular 26750

Subject

LIGO/Virgo S200114f: SAGUARO previous detection of ZTF candidate ZTF20aafeaqk (AT2020vx)

Date

2020-01-14T22:22:50Z (5 years ago)

From

Michael J. Lundquist at University of Arizona <mlundquist@email.arizona.edu>

Michael J. Lundquist, David J. Sand (UA), Kerry Paterson, Wen-fai Fong,
Jillian Rastinejad (Northwestern), Jennifer Andrews (UA), Sam Wyatt (UA),
Eric Christensen, Alex Gibbs, Frank Shelly, report on behalf of the SAGUARO
collaboration:

Following Andreoni et al. (GCN 26741Loading...
 
 ), we report a previous SAGUARO
(Lundquist et al. 2019) detection at the position of the candidate
ZTF20aafeaqk (AT2020vxLoading...
 
 ), from 2019 Nov 24.  The object was detected in a
stack of 4 images at the location of the transient (RA = 7:08:43.698, Dec
=14:38:15.336).

MJD | AB Magnitude | Error

58811.4420504 | 20.86 | 0.17

This detection was in data taken with the 1.5m Catalina Sky Survey (CSS)
telescope on Mt. Lemmon, AZ during routine operations, calibrated to Gaia G.

We believe ZTF20aafeaqk (AT2020vxLoading...
 
 ) to be unrelated to the LIGO/Virgo event
S200114f.

SAGUARO is supported by the National Science Foundation under Award Nos.
AST-1909358 and AST-1908972.

GCN Circular 26751

Subject

LIGO/Virgo S200114f: Constraints on a CCSN origin from KM3NeT MeV neutrino search.

Date

2020-01-14T22:22:57Z (5 years ago)

From

Alexis Coleiro at APC/U. Paris Diderot <coleiro@apc.in2p3.fr>

M. Colomer (APC, Universite de Paris), M. Lincetto (Aix Marseille Univ, CNRS/IN2P3, CPPM), A. Coleiro (APC, Universite de Paris), D. Dornic (Aix Marseille Univ, CNRS/IN2P3, CPPM), V. Kulikovskiy (INFN - Sezione di Genova), report on behalf of the KM3NeT Collaboration:


Using online data from the KM3NeT ORCA detector, we have performed a follow-up analysis of the recently reported gravitational-wave (GW) burst candidate S200114f (GCN #26734Loading...
 
 ) to investigate the possibility that this burst was emitted by a core-collapse supernova (CCSN) event.

KM3NeT can detect ~10 MeV neutrinos from a Galactic CCSN through a collective rise of the photomultiplier (PMT) detection rates on top of the noise, due to the Cherenkov light produced by the interaction of electron antineutrinos through inverse beta decay. This is expected mostly during the CCSN accretion phase (lasting a few hundred ms) where most of the electron antineutrinos are supposed to be emitted [1].

Two events were observed with the CCSN trigger in the KM3NeT/ORCA online infrastructure during a 400 ms time-window starting at the time of the GW trigger while 1.4 events are expected on average from the background at trigger time (p-value = 40.1%). KM3NeT/ARCA, due to a programmed upgrade of the on-shore station in Capo Passero, is off temporarily.

Using the Feldman and Cousins approach, a 90% confidence level upper limit on the number of signal events is estimated. Assuming two progenitor models from the Garching group [2] with masses of 27 Msun and 11.2 Msun, we derive a lower limit on the distance of the potential source of 11.5 kpc and 6.1 kpc respectively.

Moreover, assuming a quasi-thermal neutrino spectrum as in [2] with a spectral pinching parameter value of 3 and a mean neutrino energy of 15 MeV and assuming that 70% of the energy is released in the 400 ms, we estimate the total energy emitted into neutrinos from this GW burst candidate to be E < 2.9e53 erg at 10 kpc.

The KM3NeT detectors are currently under construction in the Mediterranean Sea. The KM3NeT/ORCA detector currently comprises an array of 4 detection lines and KM3NeT/ARCA detector hosts one line. Each detection line contains 18 digital optical modules hosting 31 directional PMTs.


[1] M. Colomer, M. Lincetto et al. (on behalf of the KM3NeT collaboration), PoS(ICRC2019)857
[2] I. Tamborra et al., Phys. Rev. D, 90 (2014)

GCN Circular 26752

Subject

LIGO/Virgo S200114f: No Counterparts in DDOTI/OAN Optical Observations

Date

2020-01-14T22:38:35Z (5 years ago)

From

Simone Dichiara at UMCP/NASA/GSFC <dichiara@umd.edu>

Simone Dichiara (GSFC/UMD), Eleonora Troja (GSFC/UMD), Alan M. Watson
(UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC/UMD), Margarita Pereyra
(UNAM), Rosa L. Becerra (UNAM), Diego Gonzalez (UNAM), William H. Lee
(UNAM) and Tanner Wolfram (ASU) report:

We observed LIGO/Virgo S200114f (Chatterjee et al, GCN Circ. 26734Loading...
 
 ) with
the DDOTI/OAN wide-field imager at the Observatorio Astronomico Nacional on
Sierra San Pedro Martir (http://ddoti.astroscu.unam.mx) on the night of
2020-01-14 UTC.

We tiled the LVC localization with four pointings spanning a region of
approximately 13.6 degrees in RA and 20.4 degrees in DEC centered on the
peak of the probability map at 07:20:09 +15:42:50 2000. This region covers
about 280 square degrees and includes about 80% of the probability in the
map. We observed from 2020-01-14 02:40 UTC to 2020-01-14 12:00 UTC (from 29
minutes to 9.7 hours after the event) obtaining exposures of 53 to 65
minutes across the field in the w filter.

We calibrate our images against the APASS catalog. Our 10-sigma limiting
magnitude are typically between w = 18.9 and w = 19.5.

We detect no uncatalogued sources within the observed field with
significant fading or brightening.

We thank the staff of the Observatorio Astronomico Nacional in San Pedro
Martir.

GCN Circular 26753

Subject

LIGO/Virgo S200114f: Candidates from SAGUARO observations

Date

2020-01-14T23:38:22Z (5 years ago)

From

Michael J. Lundquist at University of Arizona <mlundquist@email.arizona.edu>

Michael J. Lundquist, David J. Sand (UA), Jillian Rastinejad, Kerry
Paterson (Northwestern), Jennifer Andrews (UA), Wen-fai Fong,
(Northwestern), Sam Wyatt, Eric Christensen, Alex Gibbs, Frank Shelly (UA),
report on behalf of the SAGUARO collaboration:

We initiated observations of 36 fields (each 5 deg^2, totalling 180 deg^2)
within the LVC localization region for the GW trigger S200114f (LVC Circ
26734) starting on 2020-01-14 at 4:15 UT (2.12 hours after the GW trigger)
with the 1.5m Catalina Sky Survey (CSS) telescope on Mt. Lemmon, AZ.  The
typical limiting magnitudes of single pointings are G~21 mag (calibrated to
Gaia DR2).

We have posted our pointings to the Treasure Map, and encourage others to
do the same:

http://treasuremap.space/alerts?graceids=S200114f

We perform real-time processing and image subtraction (described in
Lundquist et al. 2019, ApJL, 881, 2). After discarding known moving
objects, stellar sources and known transients (cross-correlating with the
Transient Name Server and the ZTF alert stream), we find no strong
candidates that we believe to be associated with the GW event with S/N>5.
Due to the uncertain nature of the GW event however, we report 5
additional, less likely candidates below for completeness. These are
possibly variable stars or AGN. All magnitudes are based on our difference
imaging and have been calibrated to Gaia G band.

Name        | RA        | Dec        | AB Mag   | Mag Error | Notes

SAGUARO20a     07:13:08.744        14:00:07.313 20.19         0.11 (a),
(b), (c)

SAGUARO20b 06:59:34.961        22:36:29.456 19.94         0.10 (a)

SAGUARO20c 07:05:34.026        22:44:44.495 20.67         0.20 (a), (b)

SAGUARO20d     07:20:21.244        07:35:19.555 19.85         0.10 (a)

SAGUARO20e     07:04:10.181        16:27:38.455 19.29         0.07 (d)

(a) Possible Variable Star

(b) Coincident with faint PS1 source

(c) Faded by 0.78 mag over 30 min

(d) Nuclear; possible AGN

SAGUARO is supported by the National Science Foundation under Award Nos.
AST-1909358 and AST-1908972.

GCN Circular 26761

Subject

LIGO/Virgo S200114f: Upper limits from CALET observations.

Date

2020-01-15T06:27:32Z (5 years ago)

From

Yuta Kawakubo at Louisiana State U./CALET <kawakubo1@lsu.edu>

Y. Asaoka (Waseda U), A. Yoshida, T. Sakamoto, V. Pal'shin, 
S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U),
S. Nakahira (RIKEN), S. Torii (Waseda U), Y. Shimizu, 
T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), 
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 
S200114f T0 = 2020-01-14 02:08:18.239 UT (The LIGO 
Scientific Collaboration and Virgo Collaboration, GCN 
Circ. 26734Loading...
 
 ), the CALET Gamma-ray Burst Monitor (CGBM)
high voltages were off (from T0-4 min to T0+4 min).

The CALET Calorimeter (CAL) was operating in the high 
energy trigger mode at the trigger time of S200114f. Using
the CAL data, we have searched for gamma-ray events in the
10-100 GeV band from -60 sec to +60 sec from the GW trigger 
time and found no candidates in the overwrap region with the
LIGO-Virgo high probability localization region.  The 90% upper
limit of CAL is 4.7 x 10^-6 erg/cm^2/s (10-100 GeV) when the
summed LIGO-Virgo probability reaches 80%. The CAL FOV
was centered at RA= 111.2 deg, DEC= +50.7 deg at T0.

GCN Circular 26764

Subject

LIGO/Virgo S200114f: AT2020vr, AT2020vt, AT2020wa and AT2020wc 10.4m GTC spectroscopy

Date

2020-01-15T09:28:38Z (5 years ago)

From

Alberto J. Castro-Tirado at IAA-CSIC <ajct@iaa.es>

A. F. Valeev (SAO-RAS), Y.-D. Hu, A. J. Castro-Tirado and E. 
Fernandez-Garcia (IAA-CSIC), V. Sokolov (SAO-RAS), I. Carrasco and A. 
Castellon (UMA), S. B. Pandey (ARIES) and N. Castro-Rodriguez 
(GRANTECAN, IAC, ULL), on behalf of a larger collaboration, report:

Following the detection of AT2020vrLoading...
 
 /ZTF20aafdytz, 
AT2020vtLoading...
 
 /ZTF20aafemum,�� AT2020waLoading...
 
 /ZTF20aafedbk, and AT2020wcLoading...
 
 /ZTF20aafeccu 
(Andreoni et al. GCNC 26741)�� within the error area of the GW event 
S200114f (LVC, GCNC 26734), we obtained optical spectra covering the 
range 3700-7400 A with the 10.4m GTC telescope equipped with OSIRIS in 
La Palma (Spain) starting on Jan 15, 00:01 UT.

For AT2020vrLoading...
 
 /ZTF20aafdytz, we measure r= 19.80 +/- 0.02 on Jan 15, 00:08 
UT. The�� GTC spectrum is consistent with a SN Ia at about 6 days before 
maximum at redshift z = 0.213 +/- 0.001, consistent with the redshift of 
the host galaxy derived from the emission lines (z= 0.2132 +/- 0.0005).

For AT2020vtLoading...
 
 /ZTF20aafemum, we measure r = 21.49 +/- 0.07 on Jan 15, 
01:19 UT. The GTC spectrum is consistent with a SN Ia at about 7 days 
before maximum at redshift z = 0.255 +/- 0.009, consistent with the 
redshift of the host galaxy derived from the emission lines (z = 0.2528 
+/- 0.0005).

For AT2020waLoading...
 
 /ZTF20aafedbk, we measure r = 19.50 +/- 0.03 on Jan 15, 
02:00 UT. The GTC spectrum is consistent with a SN Ia at about 4 days 
before maximum at redshift z = 0.077 +/- 0.010, consistent with the 
redshift of the host galaxy derived from the emission lines (z = 0.0772 
+/- 0.0005).

For AT2020wcLoading...
 
 /ZTF20aafeccu, we measure r = 18.69 +/- 0.02 on Jan 15, 
02:11 UT. The GTC spectrum is consistent with a SN Ia at about 10 days 
before maximum at redshift z = 0.107+/- 0.009, consistent with the 
redshift of the host galaxy derived from the emission lines (z = 0.0983 
+/- 0.0005)

Therefore we consider that AT2020vrLoading...
 
 /ZTF20aafdytz, AT2020vtLoading...
 
 /ZTF20aafemum, 
AT2020waLoading...
 
 /ZTF20aafedbk and AT2020wcLoading...
 
 /ZTF20aafeccu are unrelated to the 
S200114f GW alert.

This message can be quoted.

GCN Circular 26768

Subject

LIGO/Virgo S200114f: No counterpart in targeted WHT/ACAM imaging

Date

2020-01-15T11:23:31Z (5 years ago)

From

Morgan Fraser at University College Dublin <morgan.fraser@ucd.ie>

A. Inkenhaag (Radboud Univ.), M. Fraser (University College Dublin), P. 
Jonker (SRON/Radboud Univ.)
R. Karjalainen (ING), A.J. Levan (Radboud Univ.), K. Maguire (Trinity 
College Dublin), I. Pastor Marazuela (Univ. Amsterdam) report for a 
larger collaboration:

We obtained deep imaging of a number of nearby galaxies within the sky 
localisation of the unmodeled gravitational wave burst S200114f (GCN 
26734Loading...
 
 ). Galaxies were selected from the list provided by the HOGWARTS 
code (Salmon et al. arXiv:1912.07304Loading...
 
 ); as no distance information is 
available from the GW waveform we targeted galaxies that were closer 
than 30 Mpc.

Deep (6x100s) r-band imaging was taken with the William Herschel 
Telescope + ACAM on 2020 Jan 15.1 UT. Visual comparison to PanSTARRS 
reference images reveals no obvious transients, however as the WHT 
images are deeper than those from PanSTARRS we are limited to the depth 
of the latter. We will obtain a further epoch of deep ACAM imaging over 
the coming nights that will allow us to perform difference imaging 
against these observations.

We thank the Isaac Newton Group staff and director for facilitating 
these observations.

The list of targeted galaxies follows

UGC03755������ 07:13:51.600 +10:31:14.16
NGC2350�������� 07:13:12.192 +12:15:57.60
UGC03658������ 07:04:40.080 +17:34:57.36
UGC03587������ 06:53:54.960 +19:17:58.56
UGC03876������ 07:29:17.520 +27:53:52.80
UGC03602������ 06:55:26.880 +15:56:03.84
PGC020981���� 07:25:38.880 +09:10:59.70
UGC03974������ 07:41:55.200 +16:48:11.16
PGC2807004�� 07:30:59.280 +08:00:01.80
PGC020554���� 07:16:36.120 +29:36:38.16
UGC03516������ 06:43:08.400 +22:52:27.12
PGC021614���� 07:42:31.920 +16:33:41.40
UGC03672������ 07:06:27.600 +30:19:19.20

GCN Circular 26787

Subject

LIGO/Virgo S200114f: Swift-XRT sources and observations

Date

2020-01-16T14:39:16Z (5 years ago)

From

Phil Evans at U of Leicester <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester), J.A. Kennea (PSU), A. Tohuvavohu (U.
Toronto), S.D. Barthelmy (NASA/GSFC), A.P. Beardmore (U. Leicester),
M.G. Bernardini (INAF-OAB), A.A. Breeveld (UCL-MSSL), P. Brown (TAMU),
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.W.K. Emery (UCL-MSSL), P. Giommi (ASI), C. Gronwall
(PSU), D. Hartmann (U. Clemson), H.A. Krimm (CRESST/GSFC/USRA), N.J.
Klingler (PSU), N.P.M. Kuin (UCL-MSSL), A.Y. Lien (GSFC/UMBC), F.E.
Marshall (NASA/GSFC), A. Melandri (INAF-OAB), J.A. Nousek (PSU), S.R.
Oates (U. Birmingham), P.T. O'Brien (U. Leicester), J.P. Osborne (U.
Leicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester), M.J.Page
(UCL-MSSL), D.M. Palmer (LANL), M. Perri (ASDC), J.L. Racusin
(NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU), M.H. Siegel (PSU), G.
Tagliaferri (INAF-OAB), E. Troja (NASA/GSFC/UMCP) report on behalf of
the Swift team:

Swift has carried out 206 observations of the LVC error region for the
GW trigger S200114f following the 'cWB' (version 3) GW localisation
map. The observations currently span from 6.6 ks to 99 ks after the LVC
trigger, and the XRT has covered 22.3 deg^2 on the sky (corrected for
overlaps). This covers 30% of the probability in the 'cWB' (version 3)
skymap. These pointings and associated metadata have been reported to
the Treasure Map (Wyatt et al., arXiv 2001.00588;
http://treasuremap.space/alerts?graceids=S200114f).

A 'rank 2' source has been found, so classified because it shows
indications of fading, however it is spatially consistent with a source
in the WISE AGN candidates catalogs (Assef et al., 2018) and therefore
may simply be a variable AGN. The details of this source are:
  
  Source 2:
  =============
    RA: 	 110.3641 ( = 07h 21m 27.38s) J2000
    Dec:	 +17.0360 ( = +17d 02' 09.6") J2000
    Error:	 7.0 (arcsec, radius, 90% confidence).
    Peak Rate:	 9.6e-02 +/- 1.7e-02 ct/sec (0.3-10 keV)
    Peak Flux:	 4.1e-12 +/- 7.5e-13 erg cm^-2 s^-1 (0.3-10 keV)
    Catalogued:  No
    RASS UL:	 3.5e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV)


Further observations of this source are scheduled.

In total, we have detected 8 X-ray sources. Each source is assigned a
rank of 1-4 which describes how likely it is to be related to the GW
trigger, with 1 being the most likely and 4 being the least likely. The
ranks are described at https://www.swift.ac.uk/ranks.php.

We have found:

  * 0 sources of rank 1
  * 1 source of rank 2
  * 6 sources of rank 3
  * 1 source of rank 4


RANK 3 sources
==============

These are uncatalogued X-ray sources, however they are not brighter
than previous upper limits, so do not stand out as likely counterparts
to the GW trigger.

| Source ID	 | RA		  | Dec 	   | Err90   |
|  S200114f_X1	 | 07h 13m 48.09s | +23d 04' 50.5" |	7.5" |
|  S200114f_X10  | 03h 41m 58.28s | -25d 24' 17.6" |	6.1" |
|  S200114f_X46  | 03h 41m 1.50s  | -25d 26' 54.4" |	6.4" |
|  S200114f_X56  | 07h 22m 51.63s | +16d 15' 51.0" |	6.3" |
|  S200114f_X57  | 07h 23m 54.09s | +16d 22' 00.1" |	7.7" |
|  S200114f_X58  | 07h 23m 50.42s | +16d 21' 17.1" |	6.7" |


RANK 4 sources
==============

These are catalogued X-ray sources, showing no signs of outburst
compared to previous observations, so they are not likely to be related
to the GW trigger.

| Source ID	 | RA		  | Dec 	   | Err90   |
|  S200114f_X59  |  07h 15m 9.23s | +15d 55' 36.9" |	8.3" |

The Swift-XRT observations also covered the locations of 6 sources
reported by other observers, thus:

* AT2020vrLoading...
 
  (GCN26741Loading...
 
 )		F < 3.3x10^-12 erg cm^-2 s^-1.
* AT2020vsLoading...
 
  (GCN26741Loading...
 
 )		F < 2.0x10^-12 erg cm^-2 s^-1.
* AT2020vtLoading...
 
  (GCN26741Loading...
 
 )		F < 4.2x10^-12 erg cm^-2 s^-1.
* AT2020vuLoading...
 
  (GCN26741Loading...
 
 )		F < 8.6x10^-12 erg cm^-2 s^-1.
* AT2020vwLoading...
 
  (GCN26741Loading...
 
 )		F < 4.7x10^-12 erg cm^-2 s^-1.
* AT2020wcLoading...
 
  (GCN26741Loading...
 
 )		F < 1.7x10^-11 erg cm^-2 s^-1.

Flux limits are 3-sigma upper limits on the 0.3-10 keV observed flux.

For all flux conversions and comparisons with catalogues and upper
limits from other missions, we assumed a power-law spectrum with
NH=3x10^20 cm^-2, and photon index (Gamma)=1.7

The results of the XRT automated analysis, including details of the
sources listed above, are online at
https://www.swift.ac.uk/LVC/S200114f

This circular is an official product of the Swift XRT team.

GCN Circular 26791

Subject

LIGO/Virgo S200114f: Possible X-ray transient

Date

2020-01-16T19:14:59Z (5 years ago)

From

Phil Evans at U of Leicester <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester), J.A. Kennea (PSU), A. Tohuvavohu (U.
Toronto), S.D. Barthelmy (NASA/GSFC), A.P. Beardmore (U. Leicester),
M.G. Bernardini (INAF-OAB), A.A. Breeveld (UCL-MSSL), P. Brown (TAMU),
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.W.K. Emery (UCL-MSSL), P. Giommi (ASI), C. Gronwall
(PSU), D. Hartmann (U. Clemson), H.A. Krimm (CRESST/GSFC/USRA), N.J.
Klingler (PSU), N.P.M. Kuin (UCL-MSSL), A.Y. Lien (GSFC/UMBC), F.E.
Marshall (NASA/GSFC), A. Melandri (INAF-OAB), J.A. Nousek (PSU), S.R.
Oates (U. Birmingham), P.T. O'Brien (U. Leicester), J.P. Osborne (U.
Leicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester), M.J.Page
(UCL-MSSL), D.M. Palmer (LANL), M. Perri (ASDC), J.L. Racusin
(NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU), M.H. Siegel (PSU), G.
Tagliaferri (INAF-OAB), E. Troja (NASA/GSFC/UMCP) report on behalf of
the Swift team:


We have carried out further observations of the rank 2 source (referred to as Source 2) in GCN 26787Loading...
 
 . This source,hereafter, Source S200114f_X2 has not faded between our observations, however it is detected with a 0.3-10 keV count rate of 0.069 +/- 0.0064 ct/sec.

A spectrum created from the recent XRT data can be modelled with a power-law with photon index 1.4 (+0.4, -0.3). Using this model, a 3-sigma RASS upper limit at this location translates to 0.038 ct/sec in XRT. The recent detectionis therefore nearly 5-sigma above the upper limit from RASS, accounting for the spectral shape.

As reported in GCN 26787Loading...
 
 , this source is positionally coincident with a candidate AGN, and therefore this rise in flux may indicate nothing more than AGN activity, however it could also indicate a transient source occuring in the AGN. Our position uncertainty does not allow us to confirm whether this source is in the nuclear of the WISE galaxy.

Further observations are therefore strongly encouraged.

The source position is 

    RA: 110.3641 ( = 07h 21m 27.38s) J2000
    Dec:  +17.0360 ( = +17d 02' 09.6") J2000
    Error:  7.0 arcsec, (radius, 90% confidence).

GCN Circular 26793

Subject

LIGO/Virgo S200114f: Upper Limits from Wide-Field Infrared Search with Palomar Gattini-IR

Date

2020-01-17T00:06:21Z (5 years ago)

From

Matthew Hankins at Caltech <mhankins@caltech.edu>

K. De (Caltech), M. Hankins (Caltech), M. Coughlin (Caltech), M. M. Kasliwal (Caltech), S. M. Adams (Caltech), I. Andreoni (Caltech), S. Anand (Caltech), M. Sharma (Caltech), L. Singer (NASA GSFC), T. Ahumada (UMD),  A. Moore (ANU), J. Soon (ANU), M. Ashley (UNSW), T. Travouillon (ANU), R. Soria (NAOC) 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 gravitational wave event S200114f (GCN 26734Loading...
 
 ) 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 (De et al. 2020).

We started customized Target of Opportunity observations at UT 2020-01-14 05:02. 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 479 square degrees, covering 89.1% of the probability region of the event until UT 11:21. We obtained a second epoch of observations starting the next night at at UT 2019-01-15 02:03 and continuing until UT 07:59. All data were processed and stacked with the Palomar Gattini-IR data reduction pipeline. The typical limiting magnitude of each field visit (300s second exposure time) was between 15.9 and 16.3 AB mag in J-band. No viable counterparts with at least two detections and without previous history of variability were identified in the single epoch stacks within the survey region.

GCN Circular 26796

Subject

LIGO/Virgo S200114f: ZTF Forced Photometry of the Swift Source S200114f_X2

Date

2020-01-17T06:19:19Z (5 years ago)

From

Igor Andreoni at Caltech <igor.andreoni@gmail.com>

Igor Andreoni (Caltech), Mansi M. Kasliwal (Caltech), Matthew Graham (Caltech), Frank Masci (IPAC)
On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations

The Zwicky Transient Facility (ZTF; Graham et al. 2019, Bellm et al. 2019) has repeatidly observed the location of Source S200114f_X2 (Evans et al., GCN #26787Loading...
 
 , GCN #26791Loading...
 
 ), an X-ray transient candidate possibly associated with the gravitational wave event S200114f (LVC, GCN #26734Loading...
 
 ). We used the Kowalski infrastructure (Duev et al., 2019) to query the ZTF database. Only one source, ZTF19aaehfwn, was found in ZTF data that generated >5sigma alerts within a 21-arcsec radius from Source S200114f_X2, whose position was reported with 7 arcsec uncertainty (Evans et al., GCN #26787Loading...
 
 , GCN #26791Loading...
 
 ). ZTF19aaehfwn is spatially coincident with the candidate quasar WISEA J072127.41+170205.7 (Assef et al., 2018), that is consistent with the location of Source S200114f_X2 as previously noted by Evans et al. (GCN #26787Loading...
 
 , GCN #26791Loading...
 
 ). ZTF19aaehfwn/WISEA J072127.41+170205.7 is located 3.9 arcsec away from Source S200114f_X2.

We performed forced photometry on 57 ZTF images acquired between 2018-11-17 and 2020-01-14 08:23:13, with the last image taken about 6 hours after the S200114f detection time. Forced photometry was performed on images processed through the ZTF reduction and image subtraction pipelines at IPAC (Masci et al. 2019).

The light curve of ZTF19aaehfwn shows possible long and short timescale variability, with upper limits at about r>20 before September 2019, followed by several detections at roughly 19.5 < r < 20.5 and 19.6 < g < 20.1. The light curve behavior does not appear atypical for an AGN and there is no evidence of strong flares. A decline in brightness is measured in the first hours after S200114f, as shown in the table below presenting the latest data points available.

+---------------------+--------+----------+------+
| Date (UTC)          | filter | mag (AB) | err  |
+---------------------+--------+----------+------+
| 2020-01-12 07:51:20 | r      | 19.52    | 0.19 |
| 2020-01-14 08:22:34 | r      | 19.70    | 0.11 |
| 2020-01-14 08:23:13 | r      | 20.28    | 0.18 |
+---------------------+--------+----------+------+


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; IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, 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.

GCN Circular 26803

Subject

LIGO/Virgo S200114f: No transients found in J-GEM observations of nearby galaxies

Date

2020-01-17T15:59:45Z (5 years ago)

From

Hiroki Onozato at University of Hyogo <onozato@nhao.jp>

R. Tanaka; K. Daikuhara; Y. Sekiguchi (Toho U.); K. Yanagisawa (NAOJ); T. Nakaoka; K. Takagi; M. Sasada; K. S. Kawabata (Hiroshima U.); H. Onozato, J. Takahashi (Hyogo U.); K. Ohta (Kyoto U.); F. Abe (Nagoya U.); M. Tanaka (Tohoku U.) on behalf of J-GEM collaboration

We report imaging observations for the gravitational wave event S200114f (LVC, GCN Circ. 26734Loading...
 
 ). We started our observations from 2020-01-14 17:55 UT (MJD=58862.75) about 16 hour after the event and ended at 2020-01-16 11:56 UT (MJD=58864.50).

We performed galaxy-targeted observations for 56 galaxies (see the table below) selected from the Catalog and Atlas of the LV galaxies (LVG) (Karachentsev et al., 2004) and the GLADE catalog (Dalya et al. 2018) in the probability skymap of S200114f using the following telescopes and instruments.

We found no apparent transient objects in these galaxies to 5 sigma limiting magnitudes in the AB system listed below.

   galid         ra      dec    dist  J    H    Ks   R          obsid       
-------------- -------- -------- ---- ---- ---- ---- ---- -------------------
UGCA193        150.6508 -6.0119  9.7  --   18.2 --   19.3 Kanata-HONIR       
SexA           152.7533 -4.6928  1.45 --   18.7 --   19.2 Kanata-HONIR       
MCG_-01-26-009 150.39   -6.525   9.7  --   18.3 --   18.8 Kanata-HONIR       
GALFA-Dw4      86.4367  10.7711  7.22 18.5 18.0 17.5 --   Nayuta-NIC,OAOWFC  
KKSG15         148.7937 -6.27    9.7  --   17.4 --   18.2 Kanata-HONIR       
NGC3115        151.3083 -7.7186  9.68 --   16.7 --   17.5 Kanata-HONIR       
KKSG18         151.4233 -7.9814  9.7  --   --   --   18.7 Kanata-HONIR       
UGC03303       81.2479  4.505    7.14 --   15.2 --   --   Kanata-HONIR       
KKSG17         150.41   -8.2489  9.7  --   18.2 --   18.7 Kanata-HONIR       
KK49           85.4229  6.6817   5.15 18.2 18.1 17.8 --   OAOWFC,Nayuta-NIC  
ESO483-013     63.1712  -23.1589 7.4  18.5 --   --   --   OAOWFC             
Orion          86.2583  5.0683   6.46 17.4 17.8 17.2 --   OAOWFC,Nayuta-NIC  
A0554+07       89.4029  7.4919   5.5  18.1 18.4 18.0 --   Nayuta-NIC         
IC0559         146.1829 9.6153   9.4  18.0 18.5 --   --   OAOWFC,Kanata-HONIR
DDO047         115.4792 16.8006  8.17 --   18.4 --   19.4 Kanata-HONIR       
KK65           115.63   16.5611  7.98 --   18.1 --   19.7 Kanata-HONIR       
SexDSph        153.2625 -1.6144  0.09 --   18.6 --   19.5 Kanata-HONIR       
AGC174585      114.0429 9.9864   7.73 --   18.3 --   19.5 Kanata-HONIR       
UGC03755       108.4658 10.5219  7.69 17.8 18.5 --   19.6 OAOWFC,Kanata-HONIR

    galid         ra      dec     dist    R    J    H      obsid    
--------------- -------- ------- -------- ---- ---- ---- ------------
GL071852+154033 109.7152 15.676  149.7351 19.4 --   18.1 Kanata-HONIR
GL071845+145748 109.6861 14.9632 130.0695 19.6 --   18.3 Kanata-HONIR
GL072133+151443 110.3871 15.2453 121.4037 19.8 --   18.3 Kanata-HONIR
GL071720+170810 109.3354 17.136  117.0489 20.6 --   19.1 Kanata-HONIR
GL071709+170909 109.2889 17.1524 103.1961 20.6 --   19.1 Kanata-HONIR
GL071904+173407 109.7671 17.5685 195.1108 20.7 --   19.3 Kanata-HONIR
GL071623+163821 109.0957 16.639  59.5044  19.9 --   18.7 Kanata-HONIR
GL071847+174335 109.6968 17.7263 176.0128 20.1 --   18.8 Kanata-HONIR
GL072201+145837 110.5043 14.9769 187.75   20.2 --   19.0 Kanata-HONIR
GL071622+170440 109.0936 17.0776 184.4045 17.9 --   17.4 Kanata-HONIR
GL072235+152917 110.6464 15.488  159.6764 19.8 --   18.6 Kanata-HONIR
GL072235+161218 110.6446 16.2049 116.4286 20.1 --   19.3 Kanata-HONIR
GL072220+171713 110.5836 17.2869 36.6017  19.2 --   17.8 Kanata-HONIR
GL071536+150837 108.898  15.1436 66.3962  --   18.0 --   OAOWFC      
GL071535+150837 108.8977 15.1436 69.2797  --   18.0 --   OAOWFC      
GL071543+145815 108.9296 14.9708 131.15   --   18.0 --   OAOWFC      
GL071851+133129 109.712  13.5247 65.5892  18.7 --   17.5 Kanata-HONIR
GL071452+142253 108.7168 14.3813 124.0912 19.7 --   18.5 Kanata-HONIR
GL071240+180941 108.1675 18.1615 186.3849 --   18.2 --   OAOWFC      
GL071936+124014 109.9003 12.6707 119.1697 21.1 --   19.7 Kanata-HONIR
GL071311+185631 108.2938 18.9419 145.9523 --   17.8 --   OAOWFC      
GL071204+180027 108.0146 18.0076 131.0155 --   18.2 --   OAOWFC      
GL071310+185946 108.2929 18.9961 72.2583  --   17.8 --   OAOWFC      
GL071248+184749 108.1999 18.7969 192.7041 --   17.8 --   OAOWFC      
GL071145+180852 107.9363 18.1479 155.8316 --   18.2 --   OAOWFC      
GL071150+181518 107.9597 18.2551 73.6389  --   18.2 --   OAOWFC      
GL071141+180841 107.9205 18.1448 185.7368 --   18.2 --   OAOWFC      
GL071214+184901 108.0576 18.8171 132.0515 --   17.8 --   OAOWFC      
GL071242+142548 108.1734 14.4301 122.0519 20.3 --   19.0 Kanata-HONIR
GL072527+130403 111.3637 13.0676 147.6425 15.7 --   14.5 Kanata-HONIR
GL071150+190004 107.9573 19.0012 183.6792 --   17.8 --   OAOWFC      
GL071311+134507 108.2944 13.7519 169.5679 20.3 --   19.1 Kanata-HONIR
GL071553+120654 108.969  12.1149 30.1852  --   --   19.0 Kanata-HONIR
GL072540+120523 111.4156 12.0898 132.9442 16.9 --   15.9 Kanata-HONIR
GL071105+144312 107.7713 14.7201 150.29   20.7 --   19.3 Kanata-HONIR
GL072557+120332 111.4872 12.0589 132.9218 16.9 --   --   Kanata-HONIR
GL071726+124102 109.3597 12.6838 178.0517 20.4 --   19.3 Kanata-HONIR

Kanata-HONIR: 150 cm Kanata telescope at Higashi-Hiroshima Observatory and HONIR -- a 2 channel imager (Rc and H or J) (Akitaya et al. 2014, Proc. SPIE 9147, 91474O)
Nayuta-NIC: 200 cm Nayuta telescope at Nishi-Harima Astronomical Observatory and Nishiharima Infrared Camera, NIC (J, H, Ks)
OAOWFC: 91 cm Okayama Astrophysical Observatory NIR Wide Field Camera, OAOWFC (J) (Yanagisawa et al., 2019, PASJ, 71, 118)

GCN Circular 26806

Subject

LIGO/Virgo S200114f: More candidates from the Zwicky Transient Facility

Date

2020-01-17T18:25:53Z (5 years ago)

From

Igor Andreoni at Caltech <igor.andreoni@gmail.com>

Igor Andreoni (Caltech), Tomas Ahumada (UMD), Simeon Reusch (DESY), Harsh Kumar (IITB), Michael W. Coughlin (Caltech), Leo Singer (NASA GSFC), Mansi M. Kasliwal (Caltech), Viraj Karambelkar (Caltech), Gaurav Waratkar (IITB), Shreya Anand (Caltech), Matthew Graham (Caltech), Jesper Sollerman (OKC)
on behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations

We continued observing the localization region of the unmodeled gravitational wave trigger S200114f (LVC, GCN #26734Loading...
 
 ) on 2020-01-15 starting at 08:04:13 UTC with the Palomar 48-inch telescope equipped with the 47 square degree Zwicky Transient Facility camera (ZTF, Bellm et al. 2019, Graham et al. 2019). The tiling was optimally determined and triggered using the GROWTH Target of Opportunity marshal (Coughlin et al. 2019a, Kasliwal et al. 2019b). The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC (Masci et al. 2019).

We queried the ZTF alert stream using Kowalski (Duev et al., 2019) and AMPEL (Nordin et al., 2019), requiring at least 2 detections separated by at least 15 minutes to select against moving objects. Furthermore, we cross-matched our candidates with the Minor Planet Center to flag known asteroids. We require no spatially coincident ZTF alert to be issued before the detection time of S200114f. New candidates were found within the 96% probability contour of S200114f, in addition to those reported in GCN #26741Loading...
 
 . The new transient candidates are presented in the table below.

+--------------+-----------+-------------+--------------+--------+------+----------+-------+--------+
|     Name     |  IAU Name |      RA     |     Dec      | filter | mag  |   MJD    | b_Gal | Notes  |
+--------------+-----------+-------------+--------------+--------+------+----------+-------+--------+
| ZTF20aafefpy | AT2020acfLoading...
 
  | 07:33:43.01 | +09:31:14.29 |   g    | 21.2 | 58863.38 | 13.7  | (a)(c) |
| ZTF20aafrviq | AT2020aceLoading...
 
  | 07:05:04.36 | +25:07:09.97 |   g    | 20.5 | 58863.38 | 14.0  | (a)    |
| ZTF20aafeglp | AT2020acnLoading...
 
  | 07:01:37.68 | +21:02:59.38 |   g    | 19.9 | 58863.38 | 11.6  | (b)    |
| ZTF20aafedfu | AT2020ackLoading...
 
  | 07:08:37.86 | +23:30:00.66 |   g    | 21.4 | 58863.37 | 14.1  | (c)    |
| ZTF20aafeaxv | AT2020achLoading...
 
  | 07:12:02.81 | +15:11:55.51 |   r    | 20.3 | 58862.18 | 11.3  | (d)    |
| ZTF20aafemdh | AT2020acgLoading...
 
  | 07:17:40.10 | +17:55:10.62 |   g    | 21.5 | 58863.37 | 13.7  | (e)    |
| ZTF20aafemxx | AT2020acjLoading...
 
  | 07:18:56.78 | +16:54:18.65 |   r    | 21.6 | 58862.17 | 13.6  | (e)    |
| ZTF20aafeszi | AT2020acmLoading...
 
  | 07:21:12.76 | +27:10:34.94 |   r    | 20.4 | 58862.18 | 18.1  | (e)(c) |
| ZTF20aafmdlx | AT2020zfLoading...
 
   | 03:46:00.66 | -26:50:41.00 |   g    | 19.5 | 58863.12 | -51.3 | (e)(f) |
| ZTF20aafshty | AT2020adaLoading...
 
  | 07:07:39.73 | +19:10:51.54 |   g    | 21.9 | 58862.15 | 12.1  | (c)    |
| ZTF20aafeiec | AT2020acpLoading...
 
  | 07:02:31.43 | +16:10:53.08 |   g    | 21.1 | 58862.16 | 9.7   | (g)    |
| ZTF20aafeogg | AT2020aciLoading...
 
  | 07:15:47.17 | +14:16:17.56 |   r    | 21.2 | 58862.18 | 11.8  | (g)    |
| ZTF20aafsfki | AT2020acoLoading...
 
  | 07:09:11.26 | +09:21:16.02 |   g    | 21.3 | 58863.38 | 8.2   | (g)(c) |
| ZTF20aafsero | AT2020aclLoading...
 
  | 07:15:09.53 | +13:26:43.86 |   r    | 21.4 | 58862.18 | 11.3  | (g)    |
| ZTF20aafecav | AT2020acxLoading...
 
  | 07:06:03.61 | +23:09:39.54 |   g    | 21.3 | 58863.37 | 13.3  | (e)(h) |
| ZTF20aafeolw | AT2020acyLoading...
 
  | 07:13:24.59 | +11:23:30.79 |   r    | 21.4 | 58862.18 | 9.9   | (g)    |
| ZTF20aafryfe | AT2020aczLoading...
 
  | 07:38:29.43 | +12:55:02.75 |   g    | 21.3 | 58863.38 | 16.1  | (c)    |
| ZTF20aafesaq | AT2020xbLoading...
 
   | 06:55:56.55 | +26:34:29.20 |   r    | 21.3 | 58863.39 | 12.6  | (e)(h) |
+--------------+-----------+-------------+--------------+--------+------+----------+-------+--------+
(a) offset from possible host
(b) close to a bright star, but not coincident
(c) AGN?
(d) Possible flaring activity
(e) on top of an apparently small galaxy
(f) first reported by ALeRCE
(g) coincident with a faint point source
(h) stellar?

We note that ZTF detections from 2018 and 2019 are present at the location of the SAGUAROc candidate (Lundquist et al., GCN #26753Loading...
 
 ), which further suggests that it could be a stellar variable source.


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; IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, 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 coordination is being undertaken by the GROWTH marshal system (Kasliwal et al. 2019). Alert database searches are done with using the Kowalski infrastructure (Duev et al., 2019) and with AMPEL (Nordin et al. 2019).

GCN Circular 26830

Subject

LIGO/Virgo S200114f: SOAR spectroscopy of AT2020zf, AT2020ace and AT2020ach

Date

2020-01-20T23:14:54Z (5 years ago)

From

Felipe Olivares E. at Millennium Institute of Astrophysics <felipe204@gmail.com>

Regis Cartier (CTIO/OIR lab), Felipe Olivares (INCT/UDA), ��smar Rodr��guez
(UNAB), Nicol��s Meza-Retamal (ESO Chile), Jonathan Quirola (PUC), Juanita
Antilen (U de Chile), Sahar Allam  (Fermilab), Melissa Butner (ETSU),
Douglas Tucker (Fermilab), Marcelle Soares-Santos (Brandeis U), Martin
Makler (CBPF), Clecio R. Bom (CBPF), Luidhy Santana-Silva (Valongo
Observatory), Clara Martinez-Vazquez (CTIO/OIR lab), Alyssa Garcia
(Brandeis U), Ken Herner (Fermilab), James Annis (Fermilab), Antonella
Palmese (Fermilab), Nora Sherman (Fermilab and Brandeis U), Robert Morgan
(U of Wisconsin-Madison), Tristan Bachmann (U Chicago), and Tamara Davis (U
Queensland), on behalf of the DESGW team*:



We report SOAR Goodman spectroscopy of AT2020zfLoading...
 
 , AT2020aceLoading...
 
  and AT2020achLoading...
 
 ,
possible counterparts to the unmodeled GW event S200114f reported by the
LVC in GCN Circular No. 26734. The candidates were found by ZTF (GCN
Circular No. 26806).



We obtained 1500, 2x1500 and 2x1500 sec exposures of AT2020zfLoading...
 
 , AT2020aceLoading...
 
 
and AT2020achLoading...
 
 , respectively, using the Goodman HTS instrument on the 4.1m
SOAR telescope at Cerro Pach��n. The SNID classifier analysis of these
spectra allow us to conclude that:



AT2020zfLoading...
 
  (ZTF20aafmdlx) is consistent with a Type Ia SN at a redshift of
0.136 (from host galaxy emission lines) around maximum.



AT2020aceLoading...
 
  (ZTF20aafrviq) is similar to Type II (pec) SNe at a redshift of
0.096 (from host galaxy emission lines). The low signal-to-noise spectrum
shows H-beta at ~5000 km/s on top of a blue continuum, however, H alpha
appears only in emission. Further observations are encouraged.



AT2020achLoading...
 
  (ZTF20aafeaxv) is consistent with a Type Ic-BL at a redshift of
0.155 (from the SNID analysis) a few days before peak.



The SOAR followup program is a partnership between the US (PIs: Kilpatrick
& Tucker), Chilean (PI: Olivares), and Brazilian (PI: Makler) community.
Based on observations obtained at the Southern Astrophysical Research
(SOAR) telescope, which is a joint project of the Ministerio da Ciencia,
Tecnologia, Inovacoes e Comunicacoes do Brasil (MCTIC/LNA), the U.S.
National Science Foundation's National Optical Astronomy Observatory
(NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan
State University (MSU).



*The DESGW Collaboration:



Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U),
Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas
Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico
Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U
Penn), Robert Butler (Indiana U), Melissa Butner (ETSU), Annalisa Calamida
(STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham),
Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D���Andrea (U
Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H.
Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner
(Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco
Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U
Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia
(Brandeis U), Juan Garcia-Bellido (U Aut��noma de Madrid), Mandeep Gill
(SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College
London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath
(U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard
Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin
(Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew
Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara
Martinez-Vazquez (CTIO/OIR
lab), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of
Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan
(STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth),
Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew
Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest
(STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako
(U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy
Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman
(Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of
Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI),
Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka
(NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke
Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (CTIO/OIR lab),
Alistair Walker (CTIO/OIR lab), Sara Webb (Swinburne U), Matt Wiesner
(Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo
Zenteno (CTIO/OIR lab).

GCN Circular 26848

Subject

LIGO/Virgo S200114f: Upper limits from Konus-Wind observations

Date

2020-01-22T07:26:05Z (5 years ago)

From

Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>

A. Ridnaia, S. Golenetskii, R.Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, 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 S200114f (2020-01-14 02:08:18.239 UTC, hereafter T0;
LIGO/Virgo Collaboration GCN Circ. 26734Loading...
 
 ).

No triggered KW GRBs happened ~1.5 days before and ~1.5 hours
after 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 7.9x10^-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 2.2x10^-7 erg/cm^2/s (20 - 1500 keV, 2.944 s scale).

All the quoted values are preliminary.

GCN Circular 26866

Subject

LIGO/Virgo S200114f: AstroSat CZTI upper limits

Date

2020-01-24T05:06:05Z (5 years ago)

From

Varun Bhalerao at Indian Inst of Tech <varunb@iitb.ac.in>

V. Shenoy (IITB), Aarthy E. (PRL), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao (TIFR), S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

We have carried a search for X-ray candidates in Astrosat CZTI data in a 100 sec window around the trigger time of the Burst event S200114f (UTC 2020-01-14 02:08:18, GraceDB event). We use the cWB.fits.gz,3 map (LVC GCN 26734Loading...
 
 ; https://gracedb.ligo.org/api/superevents/S200114f/files/cWB.fits.gz,3) for our analysis. CZTI is a coded aperture mask instrument that has considerable effective area for about 29% of the entire sky, but is also sensitive to brighter transients from the entire sky. At the time of burst, Astrosat's nominal pointing is RA,DEC = 12:36:35.7, 62:15:38.8 (189.1488,62.2608), which is ~71 deg away from the maximum probability location, which severely reduces the effective area of CZTI. At the time of burst event, the Earth-satellite-transient angle corresponding to maximum probability location is ~88 deg and hence is not occulted by Earth in satellite's frame. In a time interval of 100 sec around the event, the region of the localisation map which is not occulted by Earth in the satellite's frame has a cumulative probability of 0.86 (86%).

CZTI data were de-trended to remove orbit-wise background variation. We then searched data from the four independent, identical quadrants to look for coincident spikes in the count rates. Searches were undertaken by binning the data in 0.1s, 1s, and 10s respectively. Statistical fluctuations in background count rates were estimated by using data from 10 (+-5) neighbouring orbits. We selected confidence levels such that the probability of a false trigger in a 1000 sec window is 10^-4. We do not find any evidence for any hard X-ray transient in this window, in the CZTI energy range of 20-200 keV.

We use a detailed mass model of the satellite to calculate the direction-dependent instrument response for points in the visible sky. We then assume the source is modelled as a power law with photon index alpha = -1, and convert our count rate upper limits to direction-dependent flux limits. We obtain the following upper limits for source flux in the 20-200 keV band by taking a probability weighted mean over the visible sky:

0.1 s: flux limit= 4.93e-06 ergs/cm^2/s; fluence limit = 4.93e-07 ergs/cm^2
1.0 s: flux limit= 1.59e-06 ergs/cm^2/s; fluence limit = 1.59e-06 ergs/cm^2

10.0 s: flux limit= 1.99e-07 ergs/cm^2/s; fluence limit = 1.99e-06 ergs/cm^2
CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.

GCN Circular 26875

Subject

LIGO/Virgo S200114f : No significant candidates in TAROT - FRAM - GRANDMA observations

Date

2020-01-24T21:16:02Z (5 years ago)

From

Kanthanakorn Noysena at GRANDMA-n-TAROT <kanthanakorn.noysena@irap.omp.eu>

D. Corre (IJCLab), S. Antier (APC), M. Blazek (HETH/IAA-CSIC),
P. Hello (IJCLab), E. Howell (OzGrav-UWA), S. Karpov (FZU),
M. Masek (FZU), M. Prouza (FZU), M. Boer (Artemis),
N. Christensen (Artemis), L. Eymar (Artemis), A. Klotz (IRAP),
K. Noysena (Artemis, IRAP), A. Coleiro (APC), M. Coughlin (UMN),
D. Coward (OzGrav-UWA), J.G. Ducoin (IJCLab), B. Gendre (OzGrav-UWA),
D. A. Kann (HETH/IAA-CSIC), N. Kochiashvili (Iliauni),
C. Lachaud (APC), N. Leroy (IJCLab), C. Thoene (HETH/IAA-CSIC),
D. Turpin (AIM-CEA), X. Wang (THU)

report on behalf of the FRAM, TAROT and GRANDMA collaborations.

We performed tiled observations of LIGO/Virgo S200114f event
(#GCN26734) with the FRAM-Auger, FRAM-CTA-N, TAROT-Calern (TCA),
TAROT-Chili (TCH), TAROT-Reunion (TRE) telescopes.

FRAM-Auger is located at Pierre Auger Observatory. FRAM-CTA-N is
located at Observatorio del Roque de los Muchachos. TCA is located at
Calern site at the Cote d'Azur observatory. TCH is located at La Silla
  ESO observatory (LaS/ESO). TRE is located at Les Makes astronomical
observatory.

The following table shows for each telescope: the delay in minutes
from the trigger, which filter is used, the field of view of the
telescope in degrees and the typical limiting magnitude (AB mag) for a
  given exposure in seconds (s).

+-------------+---------+----------+-------------+------------+
| Telescope   | Delay   | Filter   | f.o.v.      | Limiting   |
|             | [min]   |          | [deg]       | Mag.       |
|-------------+---------+----------+-------------+------------|
| FRAM-Auger  | 19      | R        | 1.0 x 1.0   | 18.0 (60s) |
| FRAM-CTA-N  | 20      | R        | 0.45 x 0.45 | 17.0 (90s) |
| TCA         | 934     | Clear    | 1.9 x 1.9   | 18.0 (60s) |
| TCH         | 908     | Clear    | 1.9 x 1.9   | 18.0 (60s) |
| TRE         | 901     | Clear    | 4.2 x 4.2   | 17.0 (60s) |
+-------------+---------+----------+-------------+------------+

We performed the following joint tiled observations [1] :

+-------------+------------+------------+---------+---------+---------+
| Telescope   | TStart     | TEnd       | RA      | DEC     | Proba   |
|             | [UTC]      | [UTC]      | [deg]   | [deg]   | [%]     |
|-------------+------------+------------+---------+---------+---------|
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 110.225 | 16.054  | 2.0     |
|             | 02:27:00   | 02:31:27   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 110.057 | 18.973  | 1.9     |
|             | 02:32:02   | 02:36:29   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 109.029 | 18.973  | 1.8     |
|             | 02:37:04   | 02:41:31   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 110.615 | 15.081  | 1.8     |
|             | 02:42:07   | 02:46:34   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 110.306 | 14.108  | 1.8     |
|             | 02:47:10   | 02:51:36   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 110.847 | 17.027  | 1.8     |
|             | 02:52:12   | 02:56:39   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 110.455 | 18.000  | 1.8     |
|             | 02:57:13   | 03:01:40   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 110.692 | 13.135  | 1.7     |
|             | 03:02:16   | 03:06:43   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 109.609 | 15.081  | 1.6     |
|             | 03:07:17   | 03:11:44   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 109.213 | 16.054  | 1.6     |
|             | 03:12:19   | 03:16:46   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 108.603 | 15.081  | 1.6     |
|             | 03:17:20   | 03:21:47   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 108.814 | 17.027  | 1.5     |
|             | 03:22:23   | 03:26:50   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 109.432 | 18.000  | 1.5     |
|             | 03:27:25   | 03:31:52   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 108.202 | 16.054  | 1.4     |
|             | 03:32:26   | 03:36:53   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 108.409 | 18.000  | 1.4     |
|             | 03:42:46   | 03:47:13   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 110.387 | 12.162  | 1.4     |
|             | 03:48:01   | 03:52:28   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 109.304 | 14.108  | 1.4     |
|             | 03:53:03   | 03:57:30   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 108.000 | 18.973  | 1.3     |
|             | 03:58:19   | 04:02:46   |         |         |         |
| FRAM-Auger  | 2020-01-14 | 2020-01-14 | 109.392 | 12.162  | 1.2     |
|             | 04:03:23   | 04:07:50   |         |         |         |
| -----       | -----      | -----      | -----   | -----   | -----   |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 109.810 | 15.516  | 0.8     |
|             | 02:27:27   | 02:31:33   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 109.823 | 16.827  | 0.8     |
|             | 02:31:51   | 02:35:57   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 109.850 | 14.643  | 0.8     |
|             | 02:36:20   | 02:40:26   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 109.136 | 16.827  | 0.8     |
|             | 02:41:27   | 02:45:33   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 110.558 | 17.151  | 0.7     |
|             | 02:46:35   | 02:50:41   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 110.526 | 14.643  | 0.7     |
|             | 02:51:03   | 02:55:09   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 109.120 | 17.701  | 0.7     |
|             | 02:55:38   | 02:59:44   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 110.607 | 17.701  | 0.7     |
|             | 03:00:03   | 03:04:09   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 108.792 | 15.516  | 0.7     |
|             | 03:04:25   | 03:08:31   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 109.497 | 19.011  | 0.7     |
|             | 03:08:49   | 03:12:55   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 108.834 | 14.643  | 0.6     |
|             | 03:13:32   | 03:17:38   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 108.456 | 16.827  | 0.6     |
|             | 03:18:33   | 03:22:39   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 109.166 | 13.332  | 0.6     |
|             | 03:23:23   | 03:27:29   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 108.782 | 19.885  | 0.5     |
|             | 03:27:56   | 03:32:02   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 110.173 | 19.885  | 0.5     |
|             | 03:32:24   | 03:36:29   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 111.654 | 14.643  | 0.5     |
|             | 03:37:40   | 03:41:46   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 111.621 | 15.516  | 0.5     |
|             | 03:42:10   | 03:46:16   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 109.811 | 20.534  | 0.5     |
|             | 03:46:42   | 03:50:48   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 107.769 | 16.827  | 0.5     |
|             | 03:51:26   | 03:55:32   |         |         |         |
| FRAM-CTA-N  | 2020-01-14 | 2020-01-14 | 109.632 | 15.841  | 0.4     |
|             | 03:59:12   | 04:03:18   |         |         |         |
| -----       | -----      | -----      | -----   | -----   | -----   |
| TCA         | 2020-01-14 | 2020-01-14 | 85.803  | 8.351   | <0.1    |
|             | 17:41:19   | 19:42:25   |         |         |         |
| TCA         | 2020-01-17 | 2020-01-17 | 110.208 | 16.723  | 6.9     |
|             | 21:04:58   | 21:11:18   |         |         |         |
| TCA         | 2020-01-17 | 2020-01-17 | 109.521 | 14.867  | 6.7     |
|             | 21:14:59   | 21:19:09   |         |         |         |
| -----       | -----      | -----      | -----   | -----   | -----   |
| TCH         | 2020-01-14 | 2020-01-16 | 109.700 | 16.405  | 6.0     |
|             | 17:15:25   | 04:21:59   |         |         |         |
| TCH         | 2020-01-14 | 2020-01-16 | 104.050 | 16.405  | 0.1     |
|             | 17:22:11   | 04:28:31   |         |         |         |
| TCH         | 2020-01-14 | 2020-01-15 | 75.020  | 6.839   | 0.1     |
|             | 17:28:56   | 21:05:11   |         |         |         |
| TCH         | 2020-01-14 | 2020-01-16 | 111.564 | 27.314  | <0.1    |
|             | 17:48:06   | 04:54:10   |         |         |         |
| TCH         | 2020-01-14 | 2020-01-14 | 76.193  | 10.950  | <0.1    |
|             | 18:26:42   | 21:03:03   |         |         |         |
| TCH         | 2020-01-14 | 2020-01-14 | 78.264  | -3.202  | <0.1    |
|             | 18:33:27   | 21:09:51   |         |         |         |
| TCH         | 2020-01-14 | 2020-01-15 | 76.455  | -3.202  | <0.1    |
|             | 18:46:11   | 19:52:31   |         |         |         |
| TCH         | 2020-01-14 | 2020-01-15 | 75.399  | 8.657   | 0.1     |
|             | 20:04:52   | 18:41:26   |         |         |         |
| TCH         | 2020-01-14 | 2020-01-15 | 74.646  | 0.041   | 0.1     |
|             | 20:11:37   | 21:18:06   |         |         |         |
| TCH         | 2020-01-14 | 2020-01-14 | 74.646  | -1.777  | <0.1    |
|             | 20:30:45   | 20:34:55   |         |         |         |
| TCH         | 2020-01-15 | 2020-01-16 | 109.960 | 14.586  | 6.6     |
|             | 18:13:17   | 04:15:13   |         |         |         |
| -----       | -----      | -----      | -----   | -----   | -----   |
| TRE         | 2020-01-14 | 2020-01-15 | 111.429 | 16.364  | 21.1    |
|             | 17:09:18   | 23:15:34   |         |         |         |
| TRE         | 2020-01-14 | 2020-01-15 | 108.837 | 12.273  | 13.1    |
|             | 17:22:30   | 23:28:53   |         |         |         |
| TRE         | 2020-01-14 | 2020-01-15 | 113.023 | 12.273  | 6.2     |
|             | 17:34:51   | 23:41:07   |         |         |         |
| TRE         | 2020-01-14 | 2020-01-15 | 108.000 | 24.545  | 3.6     |
|             | 17:48:01   | 23:54:24   |         |         |         |
| TRE         | 2020-01-14 | 2020-01-16 | 114.146 | 20.455  | 2.0     |
|             | 18:00:24   | 00:06:41   |         |         |         |
| TRE         | 2020-01-14 | 2020-01-15 | 107.586 | 8.182   | 1.3     |
|             | 18:13:36   | 19:19:47   |         |         |         |
| TRE         | 2020-01-14 | 2020-01-16 | 115.714 | 16.364  | 0.8     |
|             | 18:25:54   | 00:32:10   |         |         |         |
| TRE         | 2020-01-14 | 2020-01-14 | 81.818  | 4.091   | 0.7     |
|             | 18:39:08   | 18:45:23   |         |         |         |
| TRE         | 2020-01-14 | 2020-01-14 | 82.759  | 8.182   | 0.7     |
|             | 18:51:24   | 18:57:40   |         |         |         |
| TRE         | 2020-01-14 | 2020-01-14 | 79.535  | 12.273  | 0.5     |
|             | 19:04:36   | 19:10:52   |         |         |         |
| TRE         | 2020-01-14 | 2020-01-14 | 58.378  | -32.727 | 0.5     |
|             | 19:16:59   | 19:23:14   |         |         |         |
| TRE         | 2020-01-14 | 2020-01-14 | 81.818  | 0.000   | 0.4     |
|             | 19:30:13   | 19:36:29   |         |         |         |
| TRE         | 2020-01-14 | 2020-01-14 | 103.500 | 24.545  | 0.4     |
|             | 19:42:29   | 19:48:45   |         |         |         |
| TRE         | 2020-01-14 | 2020-01-14 | 109.756 | 20.455  | 16.7    |
|             | 22:15:54   | 22:22:09   |         |         |         |
| TRE         | 2020-01-14 | 2020-01-15 | 104.651 | 12.273  | 0.7     |
|             | 23:45:02   | 19:51:19   |         |         |         |
| TRE         | 2020-01-15 | 2020-01-15 | 107.532 | 28.636  | 0.5     |
|             | 20:23:20   | 20:29:38   |         |         |         |
| TRE         | 2020-01-15 | 2020-01-15 | 83.721  | 12.273  | 0.4     |
|             | 20:36:32   | 20:42:49   |         |         |         |
| TRE         | 2020-01-15 | 2020-01-15 | 73.636  | 4.091   | 0.4     |
|             | 20:48:55   | 20:55:10   |         |         |         |
+-------------+------------+------------+---------+---------+---------+

TStart and TEnd refers respectively to the time of the first and last
exposure for a given tile. Observations are not necessarily continuous
  in this interval.
The Probability refers to the 2D spatial probability of the GW skymap
enclosed in a given tile.

These observations cover about 77.3% of the cumulative probability of
the CWB skymap created on 2020-01-14 02:11:51 (UTC).


The coverage map is available at:
https://grandma-owncloud.lal.in2p3.fr/index.php/s/XgtMhPRxcyL09gR/download?path=%2F&files=GRANDMA_S200114f_1579885403.png

No significant transient candidates were found during our low latency
analysis [2,3].

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 [2](https://grandma.lal.in2p3.fr/).

Details on the different telescopes are available on the GRANDMA web
pages.

[1] M. W Coughlin et al., MNRAS 2019, 
https://doi.org/10.1093/mnras/stz2485Loading...
 
 
[2] S. Antier et al., MNRAS 2019, https://doi.org/10.1093/mnras/stz3142Loading...
 
 
[3] K. Noysena et al., ApJ 2019, arXiv:1910.02770Loading...

GCN Circular 27073

Subject

LIGO/Virgo S200114f: Gemini Spectra of AT 2020vu, AT 2020vw, AT 2020vy, and AT 2020vz

Date

2020-02-15T02:15:40Z (5 years ago)

From

Curtis McCully at Las Cumbres Observatory <cmccully@lco.global>

Curtis McCully (LCO), Daichi Hiramatsu (LCO/UCSB), Jamison Burke
(LCO/UCSB), Jennifer Andrews (UA), Craig Peligrino (LCO/UCSB), D. Andrew
Howell (LCO/UCSB), Iair Arcavi (Tel Aviv University), Reinaldo de Carvalho:
(Unicid/Unicsul), 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), Gautham Narayan (UIUC), 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), Carlos Contreras (STSci), Chris
D'Andrea (UPenn), Georgios Dimitriadis (UCSC), David Jones (UCSC), Michael
Lundquist (UA), Felipe Olivares (INCT/UDA), Antonella Palmese (FNAL),
Yen-Chen Pan: (NAOJ), Daniel Scolnic (University of Chicago), WeiKang Zheng
(UC Berkeley), Antonio Bernardo (Universidade de Sao Paulo), K. 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)

Following the detection of S200114f (LIGO/Virgo Collaboration, GCN 26734Loading...
 
 ),
the Zwicky Transient Facility reported a list of possible optical
counterparts (Andreoni et al., GCN 26741Loading...
 
 ). We triggered our follow-up
program on the Gemini Telescopes (GS-2019B-Q-115; PI McCully) to classify
the candidates. We obtained optical spectra of AT 2020vuLoading...
 
 , 2020vw, 2020vy,
and 2020vz using the GMOS instrument on Gemini South. These targets were
chosen because they were visible from Chile as Gemini North was closed due
to bad weather. They were observed consecutively starting at 2020-01-16
01:55 UTC, less than 48 hours after merger detection.

These targets were triggered using the TOM Toolkit (Street et al., 2018,
arXiv 1806.09557) through Gemini's programmatic interface.

The spectra were reduced using a combination of Gemini IRAF tasks and
custom Python routines (https://github.com/cmccully/lcogtgemini). We used
both SNID (Blondin & Tonry 2007, ApJ, 666, 1024) and Superfit (Howell et
al. 2005, ApJ, 634, 1190) to classify these transients. Throughout, we
adopt a Hubble constant of H_0 =  71 km/s/Mpc and a flat cosmological model
with a dark energy density of 0.7. The classifications and spectra have
been uploaded to the Transient Name Server (TNS).



For AT 2020vzLoading...
 
 , we find a best fit using Superfit of SN 2005cl, a Type IIn
SN, at +15 days with redshift z = 0.25. This corresponds to an absolute
magnitude of -19.4, consistent with this type of supernova.
https://wis-tns.weizmann.ac.il/object/2020vz

AT 2020vyLoading...
 
  was best fit by SN 1999aa before peak brightness at z = 0.24. At
this redshift, the source has an absolute magnitude of -19.2, consistent
with a SN Ia. https://wis-tns.weizmann.ac.il/object/2020vy



AT 2020vuLoading...
 
  is consistent with a quasar. The spectrum exhibits a strong,
broad feature near 5360 A. Assuming this is Mg II, the quasar is at  z =
0.91. At this redshift, there are also spectral features consistent with
the hydrogen Balmer series and [O III].
https://wis-tns.weizmann.ac.il/object/2020vu

For AT 2020vwLoading...
 
 , the best fit is with a normal SN Ia near peak brightness at
z = 0.23, consistent with the absolute magnitude estimate of -19.0 at that
distance. https://wis-tns.weizmann.ac.il/object/2020vw

Therefore, we conclude that all of these transients (AT 2020vyLoading...
 
 , 2020vz,
2020vu, and 2020vw) are not associated with the GW alert S200114f.



We thank the Gemini team for their rapid response and assistance in
obtaining these observations.