LIGO/Virgo G270580
GCN Circular 21281
Subject
LIGO/Virgo G270580: Candidate retracted due to H1 data quality
Date
2017-06-28T23:01:02Z (8 years ago)
From
Brennan Hughey at Embry-Riddle Aeronautical U <brennan.hughey@ligo.org>
The LIGO Scientific Collaboration and Virgo Collaboration report:
In off-line reanalysis, the stretch of H1 data containing burst candidate G270580 has been removed due to an issue with data quality. Typically, a few percent of LIGO observational data are removed from analysis due to data quality concerns prior to producing final published search results (see�https://dcc.ligo.org/LIGO-P1500238/public for details). In this specific case, noise transients in H1 strain data and elevated noise in external seismic monitors were observed to correlate with periods of active snow plowing in the area. Several hours of data over the course of the winter, including the data containing candidate event G270580, were flagged as contaminated by nearby snow clearing.
GCN Circular 20862
Subject
LIGO/Virgo G270580: optical observations and classification of PS and MASTER sources
Date
2017-03-14T01:28:57Z (9 years ago)
From
Alexei Pozanenko at IKI,Moscow <grbgw.iki@gmail.com>
A. Pozanenko (IKI), A. Volnova (IKI), E. Mazaeva (IKI), E. Klunko
(ISTP), A. Kusakin (AFIF), I. Reva (AFIF), V. Rumyantsev (CrAO), R.
Inasaridze (AbAO), T. Movsisyan (BAO), A. Sergeev (IRA NASU) on behalf
of IKI-GW follow-up collaboration:
We report results of photometric observations and possible
classifications of the bright SN PS17yt, PS orphan sources PS17lk,
PS17nv, PS17qk, PS17pv, PS17rc and MASTER J090737.22+611200.5 in the
field of the LIGO G270580 localizations (LIGO Scientific Collaboration
GCN 20486). Observations were conducted using telescopes/observatories
AZT-33IK/Mondy, Zeiss-1000/TSHAO, ZTSh2.6/CrAO, AS-32/AbAO, ZTA2.6/BAO
and Zeiss-1000/Koshka.
===============
PS17lk RA 09 29 58.27 Dec +15 11 58.5
We observed the source PS17lk (Huber et al., GCN 20518) taking 6
observational sets in different epochs between Jan 25 and Feb 18. All
observations were performed with filter R. We clearly detected the
source in all but one epochs. The photometry is based on nearby SDSS stars.
Observations
date Filter MJD mid Mag(Vega) err
2017-01-25 R 57778.72969 20.92 0.16
2017-01-29 R 57782.74483 >22.5 (3 sigma uplim)
2017-01-30 R 57783.70939 21.10 0.11
2017-01-31 R 57784.69874 21.22 0.12
2017-02-07 R 57791.93095 21.60 0.40
2017-02-18 R 57802.73167 21.89 0.24
The source is not detected in any SDSS frames up to the limit of r~23.1,
i~22.8. Also there is no any source in the SDSS stacked ugriz frame. We
should note, that PS17lk is located near the ecliptic plane (ecliptic
coordinates lambda = 139.955198 deg, beta = 0.391980 deg). Upper limit
on possible proper motion of the source during 25 days of observations
is 0.6 arcsec.
===============
PS17nv 09 57 41.01 +17 49 33.4
We observed the localization of the source PS17nv (Huber et al., GCN
20518) taking 3 observational sets in different nights between Jan 25
and Jan 31. All observations were performed with filter R. We did not
detect any source no one night. The photometry is based on nearby SDSS
stars.
Observations
date Filter MJD mid 3 sigma uplim
2017-01-25 R 57778.74557 >22.2
2017-01-27 R 57780.82339 >22.2
2017-01-31 R 57784.03700 >23.4
The source is not detected in any SDSS frames up to the limit of r~23.0,
i~22.4. Also there is no any source in the SDSS stacked ugriz frame. The
source is not detected neither before the discovery (SDSS frames), nor a
few days after (our observational epochs). The PS17nv is located near
the ecliptic plane (ecliptic coordinates lambda = 145.362711 deg, beta =
5.060578 deg) and might be an uncataloged asteroid.
===============
PS17pv 09 25 07.35 +50 12 28.9
We observed the source PS17pv (Huber et al., GCN 20518) taking 3
observational sets in different epochs between Jan 25 and Jan 30. All
observations were performed with filter R. We detected the source only
on Jan 30. The photometry is based on nearby SDSS stars.
Observations
date Filter MJD mid Mag(Vega) err
2017-01-25 R 57778.82847 >20.5
2017-01-28 R 57781.86958 >22.4
2017-01-30 R 57783.80134 20.74 0.11
The source is not detected in any SDSS frames up to the limit of r~23.1,
i~22.5. Also there is no any source in the SDSS stacked ugriz frame.
===============
PS17qk 09 29 12.15 +25 49 06.4
We observed the source PS17qk (Huber et al., GCN 20518) taking 8
observational sets in different epochs between Jan 25 and Feb 18. We
performed observations with filter R and in one case in filter B. We
clearly detected the source in all our observations. The photometry is
based on nearby USNO-B1.0 stars.
Observations
date Filter MJD mid Mag(Vega) err
2017-01-25 R 57778.77275 21.01 0.12
2017-01-29 R 57782.78859 20.61 0.11
2017-01-30 R 57783.74301 20.46 0.06
2017-01-31 R 57784.73083 20.36 0.05
2017-01-31 R 57784.84479 20.50 0.03
2017-01-31 B 57784.85668 20.87 0.04
2017-02-01 R 57785.77138 20.17 0.05
2017-02-18 R 57802.75716 20.55 0.07
2017-03-06 CR 57818.86623 20.53 0.09
There is no data for this region in the SDSS latest release. We did not
find any source at the position in the archival DSS2 B and R plates up
to B~21.0, R~20.5. B-R magnitude for the source is ~0.4 mag at the epoch
Jan 31 (MJD = 57784.8). The source is unlikely a Supernova.
===============
PS17rc 09 32 19.16 +47 03 38.3
We observed the source PS17rc (Huber et al., GCN 20518) taking 5
observational sets in different epochs between Jan 25 and Feb 1. We
performed observations with filter R and in one case in filter B. We
clearly detected the source in all epochs. The photometry is based on
nearby SDSS stars.
Observations
date Filter MJD mid Mag(Vega) err
2017-01-25 R 57778.81470 20.96 0.15
2017-01-30 R 57783.77229 21.04 0.10
2017-01-31 R 57784.76358 21.13 0.11
2017-01-31 R 57784.88885 21.28 0.05
2017-01-31 B 57784.87345 23.57 0.24
2017-02-01 R 57785.80742 21.28 0.09
The source is not detected in any SDSS frames as well as in stacked
ugriz. In our observations the source is red: B-R color is ~2.3 mag at
the epoch of 2017-01-3 (MJD = 57784.9). It might be a SN well after
maximum and not related to the LIGO G270580.
===============
We observed the bright SN PS17yt (Chambers et al., GCN 20512; Huber et
al., GCN 20518) between Jan. 24 and Mar. 08 in BVR filters. We clearly
detected the source in all epochs. The preliminary light curve of the SN
may be found at http://grb.rssi.ru/PS17yt/PS17yt_lc_v7.png
The photometry is based on nearby SDSS stars.
The observed maximum of the SN in B-filter is approximately at the epoch
MJD = 57788 (B=18.09 +/-0.05 at MJD=57789.74, not corrected for Galaxy
extinction).
Riess et al. (1999, AJ 118, 2668) found that for low-redshift SNs Ia the
average rise time is t_r = 19.98 +/- 0.15 days in the rest frame for
B-band light curve. Taking into account the low redshift of the SN
PS17yt z = 0.067 (Chambers et al., GCN 20512; Malesani GCN 20527), we
may conclude that the time of the SN explosion could be at MJD = 57767 -
57768, i.e. Jan. 14-15, and most probably not related to the LIGO G270580.
===============
MASTER OT J090737.22+611200.5 09 07 37.22 +61 12 00.5
We observed the source MASTER OT J090737.22+611200.5 (Lipunov et al..
LVC 20488) taking 3 observational sets in different epochs between Jan
21 and 23. We performed observations with filter R. We clearly detected
the source in all epochs. The photometry is based on nearby SDSS stars.
Observations
date Filter MJD mid Mag(Vega) err
2017-01-21 R 57774.62327 19.07 0.01
2017-01-22 R 57775.64491 19.10 0.02
2017-01-23 R 57776.63227 19.18 0.03
The source is coincident with the SDSS QSO J090737.15+611200.7 (r =
19.75 +/- 0.02) with the redshift z = 3.751227.
GCN Circular 20669
Subject
LIGO/Virgo G270580: DLT40 follow-up observation
Date
2017-02-13T19:20:20Z (9 years ago)
From
Sheng Yang at UC Davis <sngyang@ucdavis.edu>
Sheng Yang (INAF-OAPd, UC Davis), Stefano Valenti(UC Davis), David
Sand (TTU), Leonardo Tartaglia (TTU, UC Davis), Enrico Cappellaro
(INAF-OAPd), Dan Reichart, Josh Haislip (UNC) report on behalf of the
Gravitational Wave Follow-Up by DLT40.
We report the observation of 25 galaxies within the LVC error region
for the GW trigger G270580 using the 'bayestar' GW localization map.
We selected 33 galaxies from the GWGC catalogue within 99% of the
trigger error region, within a distance of 20 Mpc, brighter
that -17.5 mag and at a Declination < 20 degree.
25 of those galaxies have been observed using the Prompt 5 telescope and are
part of the ongoing DLT40 search.
They represent the 1.33% of all galaxies within 20 Mpc
in the Glade catalogue within the LVC error region for the GW
trigger and contains 5% of all B band luminosity of those galaxies.
We started to observe these sample of galaxies on 2017-01-23 and
monitored them for 3 weeks after the GW trigger.
No interesting transients have been identified down to a limit magnitude of 19.2.
Below follow the list of galaxies observed:
Name RA(J2000) DEC(J2000) Dist(Mpc) BMAG KMAG
NGC0428 18.2317 0.9817 14.79 -19.12 -21.4648
NGC1249 47.505 -53.3359 14.19 -19.16 -21.4059
IC1954 52.8808 -51.9049 13.68 -18.98 -21.9344
NGC1546 63.6519 -56.0609 13.87 -18.21 -22.6574
IC2056 64.1022 -60.2068 15.0 -18.48 -21.7285
NGC1559 64.3989 -62.7836 12.59 -19.85 -22.4821
NGC1566 65.0016 -54.9378 6.55 -18.89 -22.1952
NGC1602 66.979 -55.0578 13.69 -18.48 -18.663
NGC1617 67.9156 -54.6019 13.87 -19.79 -23.6334
NGC1796 75.6777 -61.1399 15.0 -18.28 -21.1815
NGC1947 81.6979 -63.7613 13.87 -19.01 -23.2134
PGC018855 95.2321 -8.4956 11.22 -18.39 -21.937
NGC2283 101.4718 -18.2122 9.86 -18.17 -19.8484
ESO494-026 121.546 -27.528 14.15 -19.86 -22.8778
NGC2640 129.3526 -55.1237 12.71 -20.17 -23.8057
NGC2784 138.0813 -24.1725 9.82 -19.42 -23.6386
NGC2835 139.4703 -22.3546 8.05 -19.03 -21.612
NGC3521 166.4524 -0.0358 11.22 -20.85 -24.467
NGC4123 182.0463 2.8782 14.86 -19.09 -22.0681
NGC4178 183.1929 10.8658 14.0 -19.37 -21.1556
NGC4192 183.4513 14.8993 13.61 -20.62 -23.7813
NGC4216 183.9762 13.15 14.13 -20.58 -24.2267
NGC4419 186.7357 15.047 13.49 -19.24 -22.9131
NGC4498 187.9144 16.852 14.06 -18.54 -21.0799
NGC4571 189.2349 14.2173 14.93 -19.12 -22.3523
GCN Circular 20648
Subject
LIGO/Virgo G270580: AstroSat CZTI upper limits
Date
2017-02-09T17:09:49Z (9 years ago)
From
Varun Bhalerao at IUCAA <varunb@iucaa.in>
Sujay Mate (IUCAA), Varun Bhalerao (IUCAA), Dipankar Bhattacharya (IUCAA),
Sukanta Bose (IUCAA), Gulab Chand Dewangan (IUCAA), Ranjeev Misra
(IUCAA), Sanjit Mitra (IUCAA), A R Rao (TIFR), Tarun Souradeep (IUCAA),
Santosh Vadawale (PRL), on behalf of the Astrosat CZTI team report:
We carried out offline analysis of data from AstroSat CZTI in a 100
second window centred on the G270580 trigger time, UT 2017-01-20
12:31:00.35, to look for any coincident hard X-ray flash. CZTI is a
coded aperture mask instrument that has considerable effective area for
about 29% of the entire sky. Based on the pointing direction of AstroSat
at the time of the GW event and the LIB skymap provided by LVC
(LIB_skymap.fits.gz,0), the sky visible to CZTI has 18.6% probability of
containing the EM counterpart.
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 count rates were estimated by using data from 10
neighbouring orbits. We selected confidence levels such that the
probability of a false trigger in this 100s window is 10^-4. We do not
find any evidence for any hard X-ray transient in this window. We model
the source with a band function as used in the INTEGRAL search
(Savchenko et al, GCN Circular 20496), with alpha = 1, beta = -2.5 and
E_peak = 300 keV. The sensitivity of CZTI varies with direction. We
weight the sensitivity by the LIB probability density map to calculate
upper limits on any coincident emission from the source. In the 30-200
keV, the upper limits for source fluence in are 2.05e-07 ergs/cm^2,
4.75e-07 ergs/cm^2 and 1.36e-06 ergs/cm^2 for search timescales of 0.1,
1, and 10 seconds respectively. The corresponding flux upper limits for
the three timescales are 2.05e-06, 4.75e-07, and 1.36e-07 ergs/cm^2/sec
respectively.
Plots showing CZTI sensitivity as a function of direction for this event can be found at
https://gracedb.ligo.org/apiweb/events/G270580/files/G270580_CZTI_limits.pdf,0
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 20627
Subject
LIGO/Virgo G270580: Gemini-South Spectroscopic Classification of Optical Transients
Date
2017-02-08T10:38:35Z (9 years ago)
From
Zach Cano at U of Iceland <zewcano@gmail.com>
���S. Schulze (Weizmann Institute) & Z. Cano (IAA-CSIC) report on behalf of a
larger collaboration:
Using the 8.2-m Gemini-South telescope mounted with GMOS-S we initiated
follow-up spectral classifications of the brightest transients identified
by the Transient Name Server (TNS; https://wis-tns.weizmann.ac.il) within
the LIGO/Virgo G270580 error region. Originally hindered by bad weather,
we successfully observed two transients on 2017-01-28 (PS17rz) and
2017-01-31 (AT2017ux). Both spectroscopic classifications were performed
using SNID (Blondin & Tonry, 2007, ApJ, 666, 1024).
Survey Name | IAU Name | RA (J2000) | Dec (J2000) | Date
| Time (UT) | Grism | Exposure | Type | Phase | Redshift | Note
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
PS17rz | - | 09:36:57.18 | 29:40:06.10 |
2017-01-28 | 06:37:56 | R400 | 3 x 600s | SN Ia | pre-max |
0.151(4) | (1)
AT2017ux | SN2017ux | 09:22:53.20 | -03:12:52.30 | 2017-01-31 |
07:07:14 | R400 | 2 x 600s | SN Ia | max | 0.065(6) | (2,3)
Notes:
(1) The best-fitting templates were all SNe Ia at an average phase of -4
days before peak light.
(2) The best-fitting templates were all SNe Ia at an average phase of -1
day before peak light.
(3) Our measured SN classification (Ia) and redshift matches well with that
already reported to the TNS (z=0.07).
���
GCN Circular 20621
Subject
LIGO/Virgo G270580: ANTARES upper limits
Date
2017-02-07T11:11:25Z (9 years ago)
From
Damien Dornic at CPPM/CNRS <dornic@cppm.in2p3.fr>
M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (APC/Universite Paris Diderot), D. Dornic (CPPM/CNRS), A. Kouchner (APC/Universite Paris Diderot), T. Pradier (IPHC/Universite de Strasbourg) report on behalf of the ANTARES Collaboration:
The ANTARES Collaboration has reported in GCN 20487, no up-going muon neutrino candidate event within the 90% contour during a +/- 500s time-window centered on the G270580 event time.
The preliminary upper limit for high-energy neutrino spectral fluence (numu+anumu) as a function of the source direction assuming a E^{-2} neutrino spectrum i, and the 90% C.L. skymap contour of G270580, is reported in https://www.cppm.in2p3.fr/~dornic/events/G270580_fluenceE2.png (gwantares/ANT@GW). These neutrino fluence limits range between 1 and 3 GeV/cm^{2} depending on the source direction.
As no 3D GW localization skymap is provided, no upper limits on the total energy radiated in high-energy neutrinos can be computed for the progenitor of G270580.
ANTARES, being installed in the Mediterranean Deep Sea, is the largest neutrino detector in the Northern Hemisphere. It is primarily sensitive to astrophysical neutrinos in the TeV-PeV energy range. At 10 TeV, the median angular resolution for muon neutrinos is below 0.5 degrees. In the range 1-100 TeV, ANTARES has the best sensitivity to a large fraction of the Southern sky.
GCN Circular 20569
Subject
LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
Date
2017-02-01T15:54:33Z (9 years ago)
From
Iair Arcavi at LCOGT <iarcavi@lcogt.net>
I. Arcavi (UCSB/Las Cumbres Obs), M. Zalzman, D. Poznanski (TAU), L.P.
Singer (NASA/GSFC), D. A. Howell, C. McCully, G. Hosseinzadeh, S. Vasylyev
(Las Cumbres Obs/UCSB), S. Valenti (UC Davis), T. Piran (HUJI), D. Kasen
and J. Barnes (UC Berkeley) report on optical followup observations of
LIGO/Virgo G270580 trigger using the Las Cumbres Observatory worldwide
telescope network. We selected 50 nearby galaxies in the 90% LIGO
localization region, prioritized by their position in the localization
region, their mass, and inversely with their distance.
Of the selected 50 galaxies we were able to observe 32 with the 0.4m and 1m
Las Cumbres Observatory telescopes between Jan 21 and Jan 23. A total of
151 images were obtained in the g, r and i filters using 180 second
exposures (see full list below). Six of these images show no sources at
all, probably due to bad weather conditions (these images have no limiting
magnitudes in the list below).
Comparing to archival SDSS and DSS images, we find no obvious optical
transients.
Below is a log of the observations (CTIO = Cerro Tololo Inter-American
Observatory, Chile; SSO = Siding Spring, Australia; SAAO = South African
Astronomical Observatory, South Africa; McDonald = McDonald Observatory,
Texas, USA; Teide = Teide Observatory, Tenerife, Spain):
| Galaxy | RA | Dec | Distance [Mpc] | Time (UT) | Filter | Telescope | Airmass | 3-Sigma Limiting Mag |
| Argo Dwarf Irregular | 106.323 | -58.5204 | 5.224 | 2017-01-21 06:51:54 | g | CTIO 1m | 1.36 | 21.17 |
| Argo Dwarf Irregular | 106.323 | -58.5204 | 5.224 | 2017-01-21 06:55:50 | r | CTIO 1m | 1.37 | 21.4 |
| Argo Dwarf Irregular | 106.323 | -58.5204 | 5.224 | 2017-01-21 06:59:42 | i | CTIO 1m | 1.38 | 20.97 |
| GALEXMSC J090836.58+051727.7 | 137.152 | 5.29135 | 5.7 | 2017-01-21 07:27:22 | g | CTIO 1m | 1.36 | 21.76 |
| GALEXMSC J090836.58+051727.7 | 137.152 | 5.29135 | 5.7 | 2017-01-21 07:31:14 | r | CTIO 1m | 1.37 | 21.88 |
| GALEXMSC J090836.58+051727.7 | 137.152 | 5.29135 | 5.7 | 2017-01-21 07:35:07 | i | CTIO 1m | 1.38 | 21.44 |
| NGC 4656 NED01 | 190.990204 | 32.170288 | 5.47 | 2017-01-21 08:05:29 | g | CTIO 1m | 2.35 | 21.22 |
| NGC 4656 NED01 | 190.990204 | 32.170288 | 5.47 | 2017-01-21 08:09:26 | r | CTIO 1m | 2.33 | 21.45 |
| NGC 4656 NED01 | 190.990204 | 32.170288 | 5.47 | 2017-01-21 08:13:17 | i | CTIO 1m | 2.3 | 21.14 |
| GALEXMSC J094444.03+093657.4 | 146.183 | 9.61606 | 7.681 | 2017-01-21 13:44:39 | g | SSO 1m | 1.55 | 21.42 |
| GALEXMSC J094444.03+093657.4 | 146.183 | 9.61606 | 7.681 | 2017-01-21 13:48:34 | r | SSO 1m | 1.53 | 21.21 |
| GALEXMSC J094444.03+093657.4 | 146.183 | 9.61606 | 7.681 | 2017-01-21 13:52:26 | i | SSO 1m | 1.51 | 20.52 |
| Leo III | 149.86 | 30.7463 | 0.805 | 2017-01-21 14:36:23 | g | SSO 0.4m | 2.35 | 19.79 |
| Leo III | 149.86 | 30.7463 | 0.805 | 2017-01-21 14:39:49 | r | SSO 0.4m | 2.33 | 20.22 |
| Leo III | 149.86 | 30.7463 | 0.805 | 2017-01-21 14:43:08 | i | SSO 0.4m | 2.31 | 19.44 |
| UGC 07990 | 192.613 | 28.35283 | 6.9 | 2017-01-21 16:40:36 | g | SSO 1m | 2.53 | 20.64 |
| UGC 07990 | 192.613 | 28.35283 | 6.9 | 2017-01-21 16:44:29 | r | SSO 1m | 2.49 | 20.76 |
| UGC 07990 | 192.613 | 28.35283 | 6.9 | 2017-01-21 16:48:23 | i | SSO 1m | 2.45 | 20.35 |
| NGC 4789A | 193.521866 | 27.14963 | 4.3 | 2017-01-21 17:15:35 | g | SSO 0.4m | 2.17 | 19.17 |
| NGC 4789A | 193.521866 | 27.14963 | 4.3 | 2017-01-21 17:18:55 | r | SSO 0.4m | 2.15 | 19.6 |
| NGC 4789A | 193.521866 | 27.14963 | 4.3 | 2017-01-21 17:22:15 | i | SSO 0.4m | 2.13 | 19.07 |
| VCC 0165 | 183.972046 | 13.215795 | 3.64273 | 2017-01-21 17:27:35 | g | SSO 0.4m | 1.43 | 19.7 |
| VCC 0165 | 183.972046 | 13.215795 | 3.64273 | 2017-01-21 17:30:54 | r | SSO 0.4m | 1.43 | 19.92 |
| VCC 0165 | 183.972046 | 13.215795 | 3.64273 | 2017-01-21 17:34:15 | i | SSO 0.4m | 1.42 | 19.24 |
| SSTSL2 J125901.39+345140.4 | 194.758 | 34.86082 | 7.586 | 2017-01-21 17:51:24 | g | SSO 1m | 2.63 | 20.51 |
| SSTSL2 J125901.39+345140.4 | 194.758 | 34.86082 | 7.586 | 2017-01-21 17:55:15 | r | SSO 1m | 2.61 | 20.58 |
| SSTSL2 J125901.39+345140.4 | 194.758 | 34.86082 | 7.586 | 2017-01-21 17:59:07 | i | SSO 1m | 2.59 | 20.17 |
| ESO 154- G 023 | 44.209 | -54.57064 | 5.546 | 2017-01-21 18:45:47 | g | SAAO 1m | 1.11 | 20.76 |
| ESO 154- G 023 | 44.209 | -54.57064 | 5.546 | 2017-01-21 18:49:41 | r | SAAO 1m | 1.12 | 21.24 |
| ESO 154- G 023 | 44.209 | -54.57064 | 5.546 | 2017-01-21 18:53:36 | i | SAAO 1m | 1.12 | 20.82 |
| SSTSL2 J023747.07-612018.8 | 39.4491 | -61.34029 | 4.898 | 2017-01-21 19:12:49 | g | SAAO 1m | 1.22 | 21.65 |
| SSTSL2 J023747.07-612018.8 | 39.4491 | -61.34029 | 4.898 | 2017-01-21 19:16:44 | r | SAAO 1m | 1.23 | 21.55 |
| SSTSL2 J023747.07-612018.8 | 39.4491 | -61.34029 | 4.898 | 2017-01-21 19:20:39 | i | SAAO 1m | 1.23 | 20.87 |
| UGC 05288 | 147.821 | 7.82732 | 6.8 | 2017-01-21 21:49:46 | g | SAAO 1m | 1.7 | 21.52 |
| UGC 05288 | 147.821 | 7.82732 | 6.8 | 2017-01-21 21:53:41 | r | SAAO 1m | 1.67 | 21.39 |
| UGC 05288 | 147.821 | 7.82732 | 6.8 | 2017-01-21 21:57:35 | i | SAAO 1m | 1.65 | 20.73 |
| SDSS J095645.61+284943.4 | 149.191 | 28.82783 | 5.9 | 2017-01-21 22:20:54 | g | SAAO 1m | 2.66 | 21.09 |
| SDSS J095645.61+284943.4 | 149.191 | 28.82783 | 5.9 | 2017-01-21 22:24:47 | r | SAAO 1m | 2.62 | 20.95 |
| SDSS J095645.61+284943.4 | 149.191 | 28.82783 | 5.9 | 2017-01-21 22:28:44 | i | SAAO 1m | 2.58 | 20.33 |
| UGC 05427 | 151.17 | 29.3644 | 7.1 | 2017-01-21 22:33:53 | g | SAAO 1m | 2.66 | 21.01 |
| UGC 05209 | 146.267 | 32.2379 | 6.7 | 2017-01-21 22:50:22 | g | SAAO 1m | 2.61 | 21.3 |
| UGC 05209 | 146.267 | 32.2379 | 6.7 | 2017-01-21 22:54:19 | r | SAAO 1m | 2.58 | 21.09 |
| UGC 05209 | 146.267 | 32.2379 | 6.7 | 2017-01-21 22:58:15 | i | SAAO 1m | 2.55 | 20.45 |
| PG 1216+069:[CM2009] 11493 | 184.975 | 6.6658 | 7.5 | 2017-01-21 23:04:52 | g | SAAO 1m | 2.46 | 21.22 |
| UGC 05272b | 147.581 | 31.45604 | 7.1 | 2017-01-21 23:04:59 | g | SAAO 1m | 2.47 | 21.07 |
| PG 1216+069:[CM2009] 11493 | 184.975 | 6.6658 | 7.5 | 2017-01-21 23:08:46 | r | SAAO 1m | 2.39 | 21 |
| UGC 05272b | 147.581 | 31.45604 | 7.1 | 2017-01-21 23:08:54 | r | SAAO 1m | 2.44 | 20.94 |
| PG 1216+069:[CM2009] 11493 | 184.975 | 6.6658 | 7.5 | 2017-01-21 23:12:41 | i | SAAO 1m | 2.33 | 20.35 |
| UGC 05272b | 147.581 | 31.45604 | 7.1 | 2017-01-21 23:12:49 | i | SAAO 1m | 2.42 | 20.28 |
| IC 3142 NED01 | 184.758 | 13.98252 | 7.139 | 2017-01-21 23:20:34 | g | SAAO 1m | 2.66 | 21.07 |
| IC 3142 NED01 | 184.758 | 13.98252 | 7.139 | 2017-01-21 23:24:28 | r | SAAO 1m | 2.58 | 20.87 |
| IC 3142 NED01 | 184.758 | 13.98252 | 7.139 | 2017-01-21 23:28:23 | i | SAAO 1m | 2.51 | 20.07 |
| UGC 05186 | 145.745 | 33.26551 | 6.9 | 2017-01-21 23:35:28 | g | SAAO 1m | 2.46 | 21.04 |
| IC 3519 | 188.66 | 15.60278 | 7.611 | 2017-01-21 23:50:32 | g | SAAO 1m | 2.51 | 21.15 |
| IC 3519 | 188.66 | 15.60278 | 7.611 | 2017-01-21 23:54:25 | r | SAAO 1m | 2.45 | 21.11 |
| UGC 05186 | 145.745 | 33.26551 | 6.9 | 2017-01-21 23:56:07 | g | SAAO 1m | 2.42 | 21.38 |
| IC 3519 | 188.66 | 15.60278 | 7.611 | 2017-01-21 23:58:21 | i | SAAO 1m | 2.39 | 20.35 |
| UGC 05186 | 145.745 | 33.26551 | 6.9 | 2017-01-22 00:00:03 | r | SAAO 1m | 2.41 | 21.21 |
| UGC 05427 | 151.17 | 29.3644 | 7.1 | 2017-01-22 00:03:46 | g | SAAO 1m | 2.13 | 21.2 |
| UGC 05186 | 145.745 | 33.26551 | 6.9 | 2017-01-22 00:03:57 | i | SAAO 1m | 2.41 | 20.52 |
| UGC 05427 | 151.17 | 29.3644 | 7.1 | 2017-01-22 00:07:41 | r | SAAO 1m | 2.12 | 21.13 |
| UGC 05427 | 151.17 | 29.3644 | 7.1 | 2017-01-22 00:11:36 | i | SAAO 1m | 2.12 | 20.56 |
| SDSS J123348.08+151008.8 | 188.451 | 15.16879 | 6.4 | 2017-01-22 00:20:48 | g | SAAO 1m | 2.08 | 21.35 |
| SDSS J123348.08+151008.8 | 188.451 | 15.16879 | 6.4 | 2017-01-22 00:24:44 | r | SAAO 1m | 2.04 | 21.29 |
| UGC 05272 | 147.593 | 31.48767 | 7.1 | 2017-01-22 00:25:33 | g | SAAO 1m | 2.26 | 21.12 |
| SDSS J123348.08+151008.8 | 188.451 | 15.16879 | 6.4 | 2017-01-22 00:28:39 | i | SAAO 1m | 2.01 | 20.71 |
| UGC 05272 | 147.593 | 31.48767 | 7.1 | 2017-01-22 00:29:29 | r | SAAO 1m | 2.26 | 21.02 |
| UGC 05272 | 147.593 | 31.48767 | 7.1 | 2017-01-22 00:33:24 | i | SAAO 1m | 2.26 | 20.37 |
| UGC 05288 | 147.821 | 7.82732 | 6.8 | 2017-01-22 04:01:37 | g | CTIO 1m | 1.61 | 21.18 |
| UGC 05288 | 147.821 | 7.82732 | 6.8 | 2017-01-22 04:05:29 | r | CTIO 1m | 1.58 | 21.34 |
| UGC 05288 | 147.821 | 7.82732 | 6.8 | 2017-01-22 04:09:20 | i | CTIO 1m | 1.56 | 20.95 |
| UGC 05427 | 151.17 | 29.3644 | 7.1 | 2017-01-22 04:21:31 | g | CTIO 1m | 2.66 | 21.16 |
| UGC 05427 | 151.17 | 29.3644 | 7.1 | 2017-01-22 04:25:23 | r | CTIO 1m | 2.61 | 21 |
| UGC 05427 | 151.17 | 29.3644 | 7.1 | 2017-01-22 04:29:16 | i | CTIO 1m | 2.56 | 20.77 |
| GALEXMSC J094444.03+093657.4 | 146.183 | 9.61606 | 7.681 | 2017-01-22 04:31:58 | g | CTIO 1m | 1.48 | 21.64 |
| GALEXMSC J094444.03+093657.4 | 146.183 | 9.61606 | 7.681 | 2017-01-22 04:35:48 | r | CTIO 1m | 1.46 | 21.37 |
| GALEXMSC J094444.03+093657.4 | 146.183 | 9.61606 | 7.681 | 2017-01-22 04:39:41 | i | CTIO 1m | 1.45 | 20.88 |
| PG 1216+069:[CM2009] 11493 | 184.975 | 6.6658 | 7.5 | 2017-01-22 04:58:26 | g | CTIO 1m | 2.61 | 21.31 |
| PG 1216+069:[CM2009] 11493 | 184.975 | 6.6658 | 7.5 | 2017-01-22 05:02:18 | r | CTIO 1m | 2.53 | 21.6 |
| PG 1216+069:[CM2009] 11493 | 184.975 | 6.6658 | 7.5 | 2017-01-22 05:06:09 | i | CTIO 1m | 2.45 | 21.14 |
| SDSS J095645.61+284943.4 | 149.191 | 28.82783 | 5.9 | 2017-01-22 05:14:36 | g | CTIO 1m | 2.11 | 21.24 |
| SDSS J095645.61+284943.4 | 149.191 | 28.82783 | 5.9 | 2017-01-22 05:18:28 | r | CTIO 1m | 2.09 | 21.39 |
| SDSS J095645.61+284943.4 | 149.191 | 28.82783 | 5.9 | 2017-01-22 05:22:21 | i | CTIO 1m | 2.07 | 21.13 |
| IC 3519 | 188.66 | 15.60278 | 7.611 | 2017-01-22 05:58:25 | g | CTIO 1m | 2.35 | 21.54 |
| IC 3519 | 188.66 | 15.60278 | 7.611 | 2017-01-22 06:02:16 | r | CTIO 1m | 2.29 | 21.06 |
| SDSS J123348.08+151008.8 | 188.451 | 15.16879 | 6.4 | 2017-01-22 06:05:35 | g | CTIO 1m | 2.21 | 21.17 |
| IC 3519 | 188.66 | 15.60278 | 7.611 | 2017-01-22 06:06:10 | i | CTIO 1m | 2.24 | 20.66 |
| SDSS J123348.08+151008.8 | 188.451 | 15.16879 | 6.4 | 2017-01-22 06:09:28 | r | CTIO 1m | 2.17 | 21.23 |
| SDSS J123348.08+151008.8 | 188.451 | 15.16879 | 6.4 | 2017-01-22 06:13:21 | i | CTIO 1m | 2.12 | 20.95 |
| UGC 05272 | 147.593 | 31.48767 | 7.1 | 2017-01-22 06:47:01 | g | CTIO 1m | 2.11 | 21.18 |
| UGC 05272 | 147.593 | 31.48767 | 7.1 | 2017-01-22 06:50:55 | r | CTIO 1m | 2.11 | 20.95 |
| UGC 05272 | 147.593 | 31.48767 | 7.1 | 2017-01-22 06:54:47 | i | CTIO 1m | 2.12 | 20.47 |
| UGC 07990 | 192.613 | 28.35283 | 6.9 | 2017-01-22 08:12:12 | g | CTIO 1m | 2.06 | 21.08 |
| UGC 07990 | 192.613 | 28.35283 | 6.9 | 2017-01-22 08:16:12 | r | CTIO 1m | 2.04 | 21.01 |
| UGC 07990 | 192.613 | 28.35283 | 6.9 | 2017-01-22 08:20:04 | i | CTIO 1m | 2.02 | 20.63 |
| GALEXMSC J090836.58+051727.7 | 137.152 | 5.29135 | 5.7 | 2017-01-22 08:25:28 | g | CTIO 1m | 1.64 | 21.23 |
| GALEXMSC J090836.58+051727.7 | 137.152 | 5.29135 | 5.7 | 2017-01-22 08:29:21 | r | CTIO 1m | 1.66 | 21.13 |
| GALEXMSC J090836.58+051727.7 | 137.152 | 5.29135 | 5.7 | 2017-01-22 08:33:15 | i | CTIO 1m | 1.69 | 20.66 |
| Leo III | 149.86 | 30.7463 | 0.805 | 2017-01-22 14:32:28 | g | SSO 0.4m | 2.35 | 19.49 |
| Leo III | 149.86 | 30.7463 | 0.805 | 2017-01-22 14:35:51 | r | SSO 0.4m | 2.33 | 20.14 |
| Leo III | 149.86 | 30.7463 | 0.805 | 2017-01-22 14:39:11 | i | SSO 0.4m | 2.31 | 19.33 |
| VCC 0165 | 183.972046 | 13.215795 | 3.64273 | 2017-01-22 14:53:58 | g | SSO 0.4m | 2.33 | 19.72 |
| ESO 540- G 032 | 12.6022 | -19.90615 | 3.467 | 2017-01-22 19:43:22 | g | Teide 0.4m | 1.78 | 19.16 |
| ESO 154- G 023 | 44.209 | -54.57064 | 5.546 | 2017-01-22 21:46:03 | g | SAAO 1m | 1.57 | 21.75 |
| ESO 154- G 023 | 44.209 | -54.57064 | 5.546 | 2017-01-22 21:49:57 | r | SAAO 1m | 1.59 | 21.5 |
| ESO 154- G 023 | 44.209 | -54.57064 | 5.546 | 2017-01-22 21:53:52 | i | SAAO 1m | 1.61 | 20.78 |
| UGC 05186 | 145.745 | 33.26551 | 6.9 | 2017-01-22 22:50:27 | g | SAAO 1m | 2.67 | 17.45 |
| UGC 05186 | 145.745 | 33.26551 | 6.9 | 2017-01-22 22:54:22 | r | SAAO 1m | 2.64 | n/a |
| UGC 05186 | 145.745 | 33.26551 | 6.9 | 2017-01-22 22:58:17 | i | SAAO 1m | 2.62 | 16.77 |
| UGC 05272b | 147.581 | 31.45604 | 7.1 | 2017-01-22 23:11:44 | g | SAAO 1m | 2.41 | n/a |
| IC 3142 NED01 | 184.758 | 13.98252 | 7.139 | 2017-01-22 23:16:59 | g | SAAO 1m | 2.65 | 18.16 |
| IC 3142 NED01 | 184.758 | 13.98252 | 7.139 | 2017-01-22 23:20:53 | r | SAAO 1m | 2.57 | 18.12 |
| IC 3142 NED01 | 184.758 | 13.98252 | 7.139 | 2017-01-22 23:24:46 | i | SAAO 1m | 2.5 | 19.94 |
| UGC 05272b | 147.581 | 31.45604 | 7.1 | 2017-01-22 23:44:30 | g | SAAO 1m | 2.29 | 19.89 |
| UGC 05209 | 146.267 | 32.2379 | 6.7 | 2017-01-22 23:44:33 | g | SAAO 1m | 2.34 | 20.28 |
| UGC 05272b | 147.581 | 31.45604 | 7.1 | 2017-01-22 23:48:24 | r | SAAO 1m | 2.28 | 19.09 |
| UGC 05209 | 146.267 | 32.2379 | 6.7 | 2017-01-22 23:48:28 | r | SAAO 1m | 2.34 | 20.27 |
| UGC 05272b | 147.581 | 31.45604 | 7.1 | 2017-01-22 23:52:19 | i | SAAO 1m | 2.27 | n/a |
| UGC 05209 | 146.267 | 32.2379 | 6.7 | 2017-01-22 23:52:24 | i | SAAO 1m | 2.33 | n/a |
| NGC 1343 | 54.456913 | 72.571335 | 4.246 | 2017-01-23 00:41:15 | g | Teide 0.4m | 1.73 | 19.2 |
| Argo Dwarf Irregular | 106.323 | -58.5204 | 5.224 | 2017-01-23 02:08:17 | g | CTIO 1m | 1.18 | 21.37 |
| Argo Dwarf Irregular | 106.323 | -58.5204 | 5.224 | 2017-01-23 02:12:08 | r | CTIO 1m | 1.18 | 21.44 |
| Argo Dwarf Irregular | 106.323 | -58.5204 | 5.224 | 2017-01-23 02:16:01 | i | CTIO 1m | 1.17 | 21.16 |
| 2MASX J03325700+6633484 | 53.237503 | 66.563446 | 7.4105 | 2017-01-23 02:50:25 | g | McDonald 1m | 1.24 | 21.35 |
| 2MASX J03325700+6633484 | 53.237503 | 66.563446 | 7.4105 | 2017-01-23 02:54:20 | r | McDonald 1m | 1.24 | 20.98 |
| 2MASX J03325700+6633484 | 53.237503 | 66.563446 | 7.4105 | 2017-01-23 02:58:14 | i | McDonald 1m | 1.24 | 20.3 |
| 2MASX J03553785+6521238 | 58.907715 | 65.356613 | 4.71075 | 2017-01-23 07:00:35 | g | McDonald 1m | 1.62 | 21.49 |
| 2MASX J03553785+6521238 | 58.907715 | 65.356613 | 4.71075 | 2017-01-23 07:04:30 | r | McDonald 1m | 1.64 | 21.24 |
| 2MASX J03553785+6521238 | 58.907715 | 65.356613 | 4.71075 | 2017-01-23 07:08:24 | i | McDonald 1m | 1.65 | 20.63 |
| IC 4182 | 196.456 | 37.60495 | 4.487 | 2017-01-23 07:15:22 | g | McDonald 1m | 1.78 | 22.04 |
| IC 4182 | 196.456 | 37.60495 | 4.487 | 2017-01-23 07:19:17 | r | McDonald 1m | 1.75 | 21.82 |
| IC 4182 | 196.456 | 37.60495 | 4.487 | 2017-01-23 07:23:13 | i | McDonald 1m | 1.72 | 21.13 |
| NGC 4656 NED01 | 190.990204 | 32.170288 | 5.47 | 2017-01-23 07:28:16 | g | McDonald 1m | 1.57 | 21.69 |
| NGC 4656 NED01 | 190.990204 | 32.170288 | 5.47 | 2017-01-23 07:32:12 | r | McDonald 1m | 1.54 | 21.43 |
| NGC 4656 NED01 | 190.990204 | 32.170288 | 5.47 | 2017-01-23 07:36:07 | i | McDonald 1m | 1.52 | 20.92 |
| 2MASX J06373692+7225065 | 99.403862 | 72.418488 | 5.5 | 2017-01-23 07:41:50 | g | McDonald 1m | 1.43 | 21.59 |
| 2MASX J06373692+7225065 | 99.403862 | 72.418488 | 5.5 | 2017-01-23 07:45:49 | r | McDonald 1m | 1.43 | 21.32 |
| 2MASX J06373692+7225065 | 99.403862 | 72.418488 | 5.5 | 2017-01-23 07:49:44 | i | McDonald 1m | 1.44 | 20.66 |
| NGC 2787 | 139.82724 | 69.2034 | 7.482 | 2017-01-23 09:45:37 | g | McDonald 1m | 1.33 | 21.61 |
| NGC 2787 | 139.82724 | 69.2034 | 7.482 | 2017-01-23 09:49:37 | r | McDonald 1m | 1.33 | 22.34 |
| NGC 2787 | 139.82724 | 69.2034 | 7.482 | 2017-01-23 09:53:32 | i | McDonald 1m | 1.33 | 21.76 |
| NGC 0247 | 11.78564 | -20.760401 | 3.75 | 2017-01-23 10:50:18 | g | SSO 0.4m | 1.83 | 19.46 |
| NGC 0247 | 11.78564 | -20.760401 | 3.75 | 2017-01-23 10:53:39 | r | SSO 0.4m | 1.86 | 19.59 |
| NGC 0247 | 11.78564 | -20.760401 | 3.75 | 2017-01-23 10:57:00 | i | SSO 0.4m | 1.9 | 18.61 |
| 2MASX J01082948-2208060 | 17.122864 | -22.135002 | 2.44225 | 2017-01-23 11:05:16 | g | SSO 0.4m | 1.74 | 19.54 |
| 2MASX J01082948-2208060 | 17.122864 | -22.135002 | 2.44225 | 2017-01-23 11:08:36 | r | SSO 0.4m | 1.77 | 19.68 |
| 2MASX J01082948-2208060 | 17.122864 | -22.135002 | 2.44225 | 2017-01-23 11:11:57 | i | SSO 0.4m | 1.8 | 18.71 |
| NGC 1343 | 54.456913 | 72.571335 | 4.246 | 2017-01-23 20:15:09 | g | Teide 0.4m | 1.4 | 20.38 |
| NGC 1343 | 54.456913 | 72.571335 | 4.246 | 2017-01-23 20:18:30 | r | Teide 0.4m | 1.4 | 19.88 |
| NGC 1343 | 54.456913 | 72.571335 | 4.246 | 2017-01-23 20:21:54 | i | Teide 0.4m | 1.4 | 19.83 |
| GALEXASC J042516.20+724809.7 | 66.3189 | 72.80665 | 3.784 | 2017-01-24 00:18:34 | g | Teide 0.4m | 1.57 | 18.62 |
GCN Circular 20542
Subject
LIGO/Virgo G270580: HAWC follow-up observations
Date
2017-01-27T16:24:47Z (9 years ago)
From
Andrew Smith at U Maryland <asmith@umdgrb.umd.edu>
A. Smith (UMD) and I. Martinez (UMD)
report on behalf of the HAWC Collaboration
Subject: LIGO/Virgo G270580: HAWC follow-up observations
HAWC was operating and our real-time all-sky GRB monitoring analysis was running at the time of the G270580 event. However, the highest probability region of the LIGO/Virgo contour fell well outside the field-of-view of HAWC.
We perform a real-time search for counts above the steady-state cosmic-ray background using 4 sliding time windows (0.1, 1, 10, and 100 seconds) shifted forward in time by 10% of their width over the course of the entire day. Within each time window, we search the HAWC sky within 50 degrees of zenith using 2.1 deg x 2.1 deg square bins shifted by ~0.1 deg along the directions of Right Ascension and Declination. This analysis is tuned for detecting ~100 GeV photons and is sensitive to the most fluent GRBs. It did not report any significant post-trials events near the time of the gravitational-wave trigger.
After the trigger, we went back and re-analyzed the data within �� 60 seconds of the gravitational-wave trigger on 3 timescales (1, 10, 100 sec) to look for excesses consistent with the latest LIGO/Virgo map with a reduced threshold due to the reduced number of trials. None were found.
Additionally, we searched for long duration point sources in the 90% containment contour provided by LIGO during the following day when it transited through the HAWC field-of-view (~6hrs long transit). The highest probability region transited the HAWC field-of-view about 20hrs after the trigger. This analysis is optimized for ~0.5-100TeV. We found no evidence of emission.
HAWC is a TeV gamma ray water Cherenkov array located in the state of Puebla, Mexico that monitors 2/3 of the sky every day with an instantaneous field-of-view of ~2 sr.
GCN Circular 20536
Subject
LIGO/Virgo G270580: Swift/UVOT follow-up of PS17yt
Date
2017-01-27T08:19:18Z (9 years ago)
From
Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>
A. A. Breeveld (MSSL-UCL), S.R. Oates (U. Warwick), N.P.M. Kuin
(UCL-MSSL), S.D. Barthelmy (NASA/GSFC), A.P. Beardmore (U. Leicester),
D.N. Burrows (PSU), S. Campana (INAF-OAB), S.B. Cenko (NASA/GSFC), G.
Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB),
V.D'Elia (ASDC), P.A. Evans (U. Leicester), N. Gehrels (NASA/GSFC), P.
Giommi (ASI), C. Gronwall (PSU), J.A. Kennea (PSU), H.A. Krimm
(CRESST/GSFC/USRA), A.Y. Lien (GSFC/UMBC), D. Malesani (DARK/NBI), F.E.
Marshall (NASA/GSFC), A. Melandri (INAF-OAB), B. Mingo (U. Leicester),
J.A. Nousek (PSU), P.T. O'Brien (U. Leicester), J.P. Osborne (U.
Leicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester), 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:
The Swift/UVOT performed targeted observations of the transient PS17yt
(Chambers et al., LVC Circ. 20512), within the error area of the LIGO
event G270580, between 17:25:31 and 19:27:09 on 24th January 2017 in the
UVW2 filter. The preliminary combined magnitude using the UVOT
photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for
the exposures is 20.9 �� 0.2 mag.
GCN Circular 20532
Subject
LIGO/Virgo G270580: Fermi GBM Observations
Date
2017-01-26T17:36:20Z (9 years ago)
From
Adam Goldstein at Fermi/GBM <adam.michael.goldstein@gmail.com>
Adam Goldstein (USRA) and Colleen Wilson-Hodge (NASA/MSFC) report on
behalf of the GBM-LIGO Group:
Lindy Blackburn (CfA), Michael S. Briggs (UAH), Jacob Broida (Carleton
College),
Eric Burns (UAH), Jordan Camp (NASA/GSFC), Tito Dal Canton (NASA/GSFC),
Nelson Christensen (Carleton College), Valerie Connaughton (USRA),
Rachel Hamburg (UAH), C. Michelle Hui (NASA/MSFC), Pete Jenke (UAH),
Dan Kocevski (NASA/MSFC), Nicolas Leroy (LAL), Tyson Littenberg
(NASA/MSFC),
Julie McEnery (NASA/GSFC), Rob Preece (UAH), Judith Racusin (NASA/GSFC),
Peter Shawhan (UMD), Karelle Siellez (GA Tech), Leo Singer (NASA/GSFC),
John Veitch (Birmingham), Peter Veres (UAH)
As mentioned by Kocevski et al. (GCN 20499), Fermi was passing through the
South Atlantic Anomaly at the time of the LIGO trigger, and therefore the
GBM
detectors were disabled.
Using the Earth Occultation technique (Wilson-Hodge et al. 2012, ApJS, 201,
33)
to estimate the amount of persistent emission during a 48-hour period
centered
on the LIGO trigger time, we place the following range of 3-sigma
day-averaged
flux upper limits based on observed sources over the entire LIGO sky map:
Energy min max median
--------------------------------
12- 27 keV: 0.09 0.34 0.11 Crab
27- 50 keV: 0.13 0.42 0.17 Crab
50-100 keV: 0.20 0.70 0.26 Crab
100-300 keV: 0.32 1.28 0.43 Crab
300-500 keV: 2.58 13.2 3.64 Crab
These limits are based on the minimum requirement that each source in the
Earth
Occultation catalog was Earth-occulted at least 6 times in each of the 24
hour
periods preceding and following the LIGO trigger and that the occultations
were
well separated from nearby bright sources.
GCN Circular 20528
Subject
LIGO/Virgo G270580: MAXI/GSC observations
Date
2017-01-26T07:11:51Z (9 years ago)
From
Satoshi Sugita at Tokyo Inst. of Tech. <sugita@hp.phys.titech.ac.jp>
M. Serino (RIKEN), N. Kawai, S.Sugita (Tokyo Tech), H. Negoro (Nihon U.),
S. Ueno, H. Tomida, S. Nakahira, M. Ishikawa, Y. Sugawara (JAXA),
Y. E. Nakagawa (JAMSTEC),
T. Mihara, M. Sugizaki, W. Iwakiri, M. Shidatsu, J. Sugimoto, T.
Takagi, M. Matsuoka (RIKEN),
N.Isobe, T. Yoshii, Y. Tachibana, Y. Ono, T. Fujiwara, S. Harita, Y.
Muraki (Tokyo Tech),
A. Yoshida, T. Sakamoto, Y. Kawakubo, Y. Kitaoka (AGU),
H. Tsunemi, R. Shomura (Osaka U.),
M. Nakajima, K. Tanaka, T. Masumitsu, T. Kawase (Nihon U.),
Y. Ueda, T. Kawamuro, T. Hori, A. Tanimoto, S. Oda (Kyoto U.),
Y. Tsuboi, Y. Nakamura, R. Sasaki (Chuo U.),
M. Yamauchi, K. Furuya (Miyazaki U.),
K. Yamaoka (Nagoya U.)
report on behalf of the MAXI team:
We examined the MAXI/GSC all-sky X-ray images (2-20 keV) obtained
in the orbit and the day after the LVC trigger
G270580 at 2017-01-20 12:30:59.350 UTC (GCN 20486).
In the 92-min orbit, MAXI/GSC scanned 66.7%
of the whole sky, which includes 78.5% of the
90% regions in the LIB skymap.
One day image covers 96.6% of the 90% regions
in the LIB skymap.
No significant new source was found in these images.
The upper limits for the X-ray flux are different depending
on the part of the sky.
For instance, typical 2-20 keV 1-sigma (3-sigma) upper limits obtained
from the one-orbit and oneday images are
13 (40) mCrab and 5 (16) mCrab, respectively.
GCN Circular 20527
Subject
LIGO/Virgo G270580: NOT observations of PS17yt
Date
2017-01-25T19:35:48Z (9 years ago)
From
Daniele Malesani at DARK/NBI <malesani@dark-cosmology.dk>
D. Malesani (DARK/NBI), G. Leloudas (WIS, DARK/NBI), E. Pian (SNS Pisa),
L. A. Antonelli (INAF/OAR), S. Benetti (INAF/OAPd), M. Branchesi (Univ.
Urbino), E. Brocato (INAF/OAR), S. Campana (INAF/OABr), E. Cappellaro
(INAF/OAPd), S. Covino (INAF/OABr), P. D'Avanzo (INAF/OABr), V. D'Elia
(INAF/OAR; ASI/ASDC), J. P. U. Fynbo (DARK/NBI), A. Grado (INAF/OAC), G.
Greco (Univ. Urbino), J. Hjorth (DARK/NBI), A. Melandri (INAF/OABr), B.
Milvang-Jensen (DARK/NBI), E. Palazzi (INAF/IASF Bo), D. A. Perley
(DARK/NBI), S. Piranomonte (INAF/OAR), A. Stamerra (INAF/OATo), G.
Stratta (Univ, Urbino), G. Tagliaferri (INAF/OABr), L. Tomasella
(INAF/OAPd), and D. J. Watson (DARK/NBI), report:
We observed the transient PS17yt (Chambers et al., LVC Circ. 20512)
within the error area of the LIGO event G270580, using the Nordic
Optical Telescope (NOT) equipped with the AlFOSC instrument. Two spectra
by 1200 s were acquired starting on 2017 Jan 25 at 01:05 UT (4.5 days
after the GW event), covering the wavelength range 3500-9000 AA.
Using SNID (Blondin & Tonry 2007, ApJ, 666, 1024) we confirm that the
object is a type-Ia SN approximately 1 week before maximum, consistent
with the findings of Castro-Tirado et al. (LVC Circ. 20521) and
Copperwheat et al. (LVC Circ. 20526). In agreement with Copperwheat et
al. (LVC Circ. 20526), the matching SN template indicates a redshift z =
0.068 +- 0.004, consistent with the SDSS spectroscopic redshift of a
nearby galaxy (z = 0.0698) first noted by Chambers et al. (LVC Circ. 20512).
We acknowledge excellent support from the NOT observing staff, in
particular Emanuel Gafton and Thomas Augusteijn.
GCN Circular 20526
Subject
LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
Date
2017-01-25T16:41:59Z (9 years ago)
From
Chris Copperwheat at LJMU ArI <c.m.copperwheat@ljmu.ac.uk>
From C.M. Copperwheat (LJMU), A.S. Piascik (LJMU), D.Steeghs (Warwick)
and I.A. Steele (LJMU) on behalf of a larger collaboration.
We report the following Liverpool Telescope follow-up observations of
EM candidates reported to the collaboration in GCN 20518. Observations
were made with the SPRAT spectrograph, and supernova classifications
were obtained using SNID (Blondin & Tonry, 2007, ApJ, 666, 1024).
PS17wt was observed on 2017-01-25 at 00:30 UT. Possibly some faint
emission features - no clear evidence of transient distinct from host
galaxy emission.
PS17yt was observed on 2017-01-25 at 01:50 UT. The spectrum is
consistent with a SN Type Ia at 9 days before peak, with z=0.069.
Galaxy 2MASX J10035883+4902195 is at a 0.211 arcmin separation, and
has catalogue z=0.069742. The classification of this object as a Type
Ia is consistent with GCN 20521, which reports spectroscopic data
obtained an hour prior to our observation.
PS17tn was observed on 2017-01-25 at 02:37 UT. The spectrum is
consistent with a SN Type Ia at 2 days before peak, with z=0.040.
Galaxy 2MASX J09431321+4118581 is at a 0.099 arcmin separation, and
has catalogue z=0.044759.
PS17ua was observed on 2017-01-25 at 03:12 UT. The spectrum is
consistent with a SN Type Ia at 1 day before peak, with z=0.048.
Galaxy 2MASX J09441179+3250341 is at a 0.102 arcmin separation, and
has catalogue z=0.045336.
PS17of was observed on 2017-01-25 at 03:49 UT. The spectrum is
consistent with a SN Type II at 15 days after peak, with z=0.031.
--
------------------------------------------------------
C.M.Copperwheat
Astrophysics Research Institute,
Liverpool John Moores University
------------------------------------------------------
http://telescope.livjm.ac.uk
------------------------------------------------------
Email: c.m.copperwheat@ljmu.ac.uk
Tel: +44 (0)151 231 2914
Fax: +44 (0)151 231 2921
------------------------------------------------------
GCN Circular 20524
Subject
LIGO/Virgo G270580: Asiago 1.82m observations of PS17ua and PS17yt
Date
2017-01-25T11:03:02Z (9 years ago)
From
Andrea Melandri at INAF-OAB <andy.melandri@gmail.com>
L. Tomasella, E. Cappellaro, A. Pastorello, S.Yang (INAF-OAPd), L. Amati (INAF-IASF Bo), L. A. Antonelli, (INAF-OAR), S. Ascenzi (INAF-OAR), M. T. Botticella (INAF-OAC), M. Branchesi (Urbino University/INFN Firenze), S. Campana (INAF-OAB), S. Covino, P. D'Avanzo (INAF-OAB), V. D'Elia (INAF-ASDC), F. Getman (INAF-OAC), A. Grado (INAF-OAC), G. Greco (Urbino University/INFN Firenze), L. Limatola (INAF-OAC), M. Lisi (INAF-OAR), A. Melandri (INAF-OAB), L. Nicastro (INAF-IASF Bo), E. Palazzi (INAF-IASF Bo), E. Pian (SNS-Pisa), S. Piranomonte (INAF-OAR), L. Pulone (INAF-OAR), A. Rossi (INAF-IASF Bo), G. Stratta (Urbino University/INFN Firenze), G. Tagliaferri (INAF-OAB), V. Testa (INAF-OAR), E. Brocato (INAF-OAR) on behalf of GRavitational Wave Inaf TeAm report:
The transients PS17ua (Huber et al., LVC GCN 20518) and PS17yt (Chambers et al., LVC GCN 20512) were observed with 1.82m Copernico telescope (INAF-OAPd; equipped with AFOSC, range 340-820nm, resolution 1.4 nm).
PS17ua was observed in spectroscopic mode for 2400 sec, starting at 2017-01-24.920 UT.
The spectrum shows that this transient is a Type Ia SN, about one week before maximum light, at a redshift ~0.051, which is consistent with the photometric redshift of the host galaxy provided by SDSS-DR13 (photoZ (KD-tree method)=0.067+/-0.017 and photoZ (RF method)=0.059+/-0.021).
We also measured for PS17ua the following Sloan AB magnitudes: g=17.67, r=17.61, i=18.15 +/-0.01. The classification was performed using the GELATO (Harutyunyan et al. 2008, A&A, 488, 383) and SNID (Blondin and Tonry 2007, ApJ, 666, 1024) tools.
PS17yt was observed in photometric mode in the ugriz bands on 2017-01-24.982 UT, measuring the following Sloan AB magnitudes: g=18.881+/-0.015, r=19.022+/-0.017, i=19.179+/-0.031, z=19.46+/-0.07, u=19.54+/-0.04. We also measured the following Vega magnitudes: B-Bessell=18.92+/-0.02, V-Bessell=18.94+/-0.03.
GCN Circular 20523
Subject
LIGO/Virgo G270580: Swift-XRT follow-up of PS17yt
Date
2017-01-25T09:30:05Z (9 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans (U. Leicester), J.A. Kennea (PSU), S.D. Barthelmy
(NASA/GSFC), A.P. Beardmore (U. Leicester), A.A. Breeveld (UCL-MSSL),
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), N. Gehrels (NASA/GSFC), P. Giommi (ASI), C. Gronwall
(PSU), H.A. Krimm (CRESST/GSFC/USRA), N.P.M. Kuin (UCL-MSSL), A.Y. Lien
(GSFC/UMBC), D. Malesani (DARK/NBI), F.E. Marshall (NASA/GSFC), A.
Melandri (INAF-OAB), B. Mingo (U. Leicester), J.A. Nousek (PSU), S.R.
Oates (U. Warwick), P.T. O'Brien (U. Leicester), J.P. Osborne (U.
Leicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester), D.M.
Palmer (LANL), M. Perri (ASDC), J.L. Racusin (NASA/GSFC), 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 observed the location of the bright transient PS17yt (Chambers et
al., LVC Circ. 20512) for 3ks, from 17:25:27 UT to 19:27:07 UT on 2017
January 24.
No X-ray source is detected at the location of PS17yt. The 3-sigma upper
limit is 3.1e-3 ct/sec. For a typical AGN power-law spectrum (NH=3e20,
Gamma=1.7) this corresponds to an observed flux of 1.28e-13 erg cm^-2 s^-1.
This circular is an official produce of the Swift-XRT team.
GCN Circular 20522
Subject
LIGO/Virgo G270580: GMG photometric follow-up of PS17yt
Date
2017-01-25T09:24:59Z (9 years ago)
From
Jinzhong Liu at Xinjiang Astronomical Observatory <liujinzh@xao.ac.cn>
J. Mao (YNAO/CAS), D. Xu (NAO/CAS), J.M. Bai (YNAO/CAS), H.B. Zhao, B.
Li (PMO/CAS), J.Z. Liu, H.B. Niu, Y. Zhang, X. Zhang, G.X. Pu, S.G. Ma,
T.Z. Yang, F.F. Song (XAO/CAS), T.M. Zhang, X. Zhou, H.X. Feng, Z.P. Zhu
(NAO/CAS) report on behalf of the Gravitational Wave Follow-Up Network
by NAO-PMO-XAO-YNAO in China (GWFUNC):
We observed the transient, PS17yt, in Chambers et al. (GCN 20512) using the
Gao-Mei-Gu (GMG) 2.4-m telescope at Lijiang, Yunan, China. The
photometric observation began at 18:35:37 UT on 2017-01-24, and 1x600 s
imaging was obtained in the Sloan r-filter . The object was well
detected with the magnitude of m(r) = 18.76 �� 0.04 mag, calibrated with
nearby SDSS stars. Together with the previous measurements in GCN 20512,
it indicates that the object has been rising relatively slowly, being
more consistent with the behavior of early SN Ia than those of other
types of early SNe, in agreement with its spectroscopic classification
of SN Ia in Castro-Tirado et al. (GCN 20521).
GCN Circular 20521
Subject
LIGO/Virgo G270580: 10.4m GTC spectroscopic observations of PS17yt
Date
2017-01-25T05:47:02Z (9 years ago)
From
Alberto J. Castro-Tirado at IAA-CSIC <ajct@iaa.es>
A. J. Castro-Tirado, V. Casanova, B.-B. Zhang, J. C. Tello, Y. Hu
(IAA-CSIC, Granada), M. D. Caballero-Garcia (ASU-CAS), V. V. Sokolov, V.
V. Vlasjuk, A. F. Valeev (SAO-RAS), E. Pian (SNS-Pisa), S. Jeong (SKKU),
S. R. Oates (Warwick), S. Geier and D. P��rez (GRANTECAN), report:
We observed the transient PS17yt (Chambers et al., LVC GCN 20512) with
the 1.5m OSN telescope at Sierra Nevada (Spain) in imaging mode and with
the 10.4m GTC telescope located at La Palma (Canary Islands, Spain)
equipped with the OSIRIS spectrograph. The OSN images were gathered on
Jan 24, 21:54 UT, whereas the spectroscopic observations were carried
out starting on Jan 25, 00:50 UT. The PS17yt spectrum covering the range
3700-10000 A shows that this transient is a type Ia SN about 1 week
before maximum at a redshift z~0.026.
We acknowledge excellent support from the GTC staff.
GCN Circular 20520
Subject
LIGO/Virgo G270580: No change to estimate of LIGO false alarm probability
Date
2017-01-25T03:02:04Z (9 years ago)
From
Peter Shawhan at U of Maryland/LSC <pshawhan@umd.edu>
The LIGO Scientific Collaboration and Virgo report:
The Coherent WaveBurst event candidate of 2017-01-20, with GraceDB ID
G270580, was initially reported (LSC and Virgo, GCN 20486) with an
estimated false alarm rate (FAR) of 1.6e-7 Hz, or about 5 per year.
Offline re-analysis has not changed this estimate. At this time, we
do not have any evidence suggesting that the significance of this
event will increase on further study.
GCN Circular 20519
Subject
LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
Date
2017-01-24T20:49:27Z (9 years ago)
From
Chris Copperwheat at LJMU ArI <c.m.copperwheat@ljmu.ac.uk>
From C.M. Copperwheat , A.S. Piascik and I.A. Steele (Liverpool JMU)
on behalf of a larger collaboration.
We report the following Liverpool Telescope follow-up observations of
EM candidates reported to the collaboration by other groups.
Observations were made with the SPRAT spectrograph, and supernova
classifications were obtained using SNID (Blondin & Tonry, 2007, ApJ,
666, 1024).
The following transients were originally reported in GCN 20493.
MASTER OT J063256.50-212333.4 was observed on 2017-01-22 at 21:47 UT.
We find this object has faded considerably, measuring an unfiltered
magnitude of > 20 in the acquisition image, suggesting it has faded
back to or close to its quiescent brightness, reported in GCN 20493 as
20.7. This would be consistent with their tentative classification of
this object as a UVCet flare.
MASTER OT J072347.17+041144.0 was observed on 2017-01-22 at 22:39 UT.
We find a faint object at these coordinates, with an estimated
unfiltered magnitude of ~20.5 based on the acquisition image. No
spectrum was obtained.
MASTER OT J073310.71-012307.3 was observed on 2017-01-22 at 23:04 UT.
We find a featureless spectrum consistent with the tentative
classification of this object in GCN 20493 as a dwarf nova outburst.
MASTER OT J075227.62+113311.6 was observed on 2017-01-22 at 23:29 UT.
The spectrum we obtained is fairly poor but there is some evidence of
emission features, consistent with the tentative classification of
this object in GCN 20493 as a QSO flare.
MASTER OT J073330.60+203432.7 was observed on 2017-01-23 at 00:01 UT.
We find a faint object at these coordinates, with an estimated
unfiltered magnitude of ~21 based on the acquisition image. No
spectrum was obtained.
MASTER OT J081506.13+381123.3 was observed on 2017-01-23 at 00:26 UT.
The spectrum is consistent with a SN Type Ia at +8 days, with z=0.057.
MASTER OT J081016.59+335347.5 was observed on 2017-01-23 at 01:44 UT.
We do not detect a transient distinct from the host galaxy emission.
MASTER OT J074554.47+283123.8 was observed on 2017-01-23 at 23:47 UT.
We detect no transient in the acquisition image at the object
coordinates. We estimate the limiting magnitude of this exposure to be
~20.7.
MASTER OT 103001.37+680122.3 was observed on 2017-01-24 at 00:19 UT.
We find a featureless spectrum consistent with the tentative
classification of this object in GCN 20493 as a dwarf nova outburst.
In addition, candidate PTSS-17dfn was reported in GCN 20497. We
observed this transient on 2017-01-24 at 01:49 UT. The spectrum is
consistent with a SN Type Ia at maximum, with z=0.085.
--
------------------------------------------------------
C.M.Copperwheat
Astrophysics Research Institute,
Liverpool John Moores University
------------------------------------------------------
http://telescope.livjm.ac.uk
------------------------------------------------------
Email: c.m.copperwheat@ljmu.ac.uk
Tel: +44 (0)151 231 2914
Fax: +44 (0)151 231 2921
------------------------------------------------------
GCN Circular 20518
Subject
LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
Date
2017-01-24T18:15:12Z (9 years ago)
From
S. J. Smartt at Queens U Belfast <s.smartt@qub.ac.uk>
M. E. Huber (IfA), K. C. Chambers (IfA), K. W. Smith (QUB),
D. R. Young, S. J. Smartt, (QUB),, M. Coughlin (Harvard), T.-W. Chen
(MPE), L. Denneau, H. Flewelling, A. Heinze, E. A. Magnier (IfA),
A. Rest (STScI), B. Stalder (IfA), A. S. B. Schultz, C. W. Stubbs
(Harvard) J. Tonry, C. Waters, R. J. Wainscoat, H. Weiland (IfA),
D. E. Wright (QUB)
With Pan-STARRS1, we surveyed the primary northern area of the
LALInference map (LIB_skymap.fits ; Veitch et al., PRD 91, 042003, GCN
20486) following the release of the G270580 alert. Observations began
57774.4 UT and lasted over two further nights. The map of pointings is
uploaded on GraceDB.
Images were taken in the Pan-STARRS i-band in a series of overlapping
45s exposures, with typically 4-8 images at each position. These were
combined into stacks and subtracted from the Pan-STARRS1 3Pi reference
image (Chambers et al. arXiv:1612.05560, and available at
http://panstarrs.stsci.edu). We reach approximately i~21-21.5
depending on the number of images combined.
Using techniques discussed in Smartt et al. (2016, MNRAS, 462, 4094),
we have located and vetted transients with quality filters and a
machine learning algorithm on the images.
In the following table, we give our 124 targets, sorted by magnitude.
The lightcurve trend is given (LC trend), indicating the change in
magnitude between earliest and latest MJD of detection. To select
these targets we required a minimum of 2 detections over 2 separate
nights.
Variable sources which are likely AGN/QSOs or variable stars have, as
far as possible, been removed from this transient list. We remove
likely AGN/QSOs either from catalogues, SDSS DR12 spectra, or nuclear
transients which in galaxies with previous core variability seen in
Pan-STARRS general survey mode. Similarly variable stars or stellar
outbursts are removed through catalogue matching. The following list
is composed of SN-like transients, to the best of our knowledge to
date.
We have removed previously known supernovae (in the preceding weeks
before G270580) from this list. We recover PTSS-17dfn and PTSS-17dgm
from Zhao et al. (GCN 20497,20506 ; the other is outside our field).
The list is sorted by magnitude and we recommend prioritising objects
for follow-up which are rising/falling in their lightcurve.
sn = likely SN, offset from plausible host
nt = nuclear transient. Not obvious AGN, but transient coincident with galaxy core
orphan = no obvious host
Name RA (J2000) Dec (J2000) type current trend Disc. MJD Disc Mag
PS17ua 09 44 11.39 +32 50 36.7 sn fading 00.01 (i-i) 57774.46 17.79
PS17of 10 02 34.60 +44 47 11.2 sn rising 00.07 (i-i) 57774.47 18.53
PS17tn 09 43 13.64 +41 19 02.2 sn rising 00.43 (i-i) 57774.47 18.81
PS17yh 09 59 44.73 +27 38 54.6 sn rising 00.01 (i-i) 57774.53 19.03 PTSS-17dfn
PS17so 09 39 11.89 +45 22 25.9 nt fading 00.01 (i-i) 57774.47 19.24
PS17tp 09 43 15.22 +27 33 07.5 sn fading 00.22 (i-i) 57774.54 19.25
PS17qr 09 30 36.59 +21 24 42.5 sn fading 00.02 (i-i) 57774.51 19.33 PTSS-17dgm
PS17xv 09 58 15.93 +33 28 16.7 sn fading 00.18 (i-i) 57774.47 19.55
PS17yt 10 03 57.96 +49 02 28.3 sn rising 00.54 (i-i) 57774.47 19.71
PS17wt 09 53 23.49 +60 09 31.5 sn rising 00.19 (i-i) 57774.46 19.86
PS17nj 09 50 24.19 +63 35 07.7 nt fading 00.01 (i-i) 57774.46 19.87
PS17ta 09 40 49.20 +27 50 41.2 nt rising 00.01 (i-i) 57774.54 19.88
PS17ve 09 48 07.40 +33 05 12.3 sn fading 00.09 (i-i) 57774.46 19.98
PS17st 09 39 36.56 +46 17 25.1 sn fading 00.10 (i-i) 57774.46 20.00
PS17mc 09 36 03.65 +51 23 16.0 sn rising 00.12 (i-i) 57774.47 20.02
PS17pp 09 21 01.11 +49 27 47.0 sn rising 00.21 (i-i) 57774.48 20.07
PS17mr 09 42 43.78 +42 28 58.9 nt fading 00.06 (i-i) 57774.46 20.08
PS17pt 09 23 31.33 +52 49 13.3 sn rising 00.02 (i-i) 57774.45 20.09
PS17pm 09 18 21.83 +64 43 50.0 nt rising 00.12 (i-i) 57774.46 20.11
PS17va 09 47 39.20 +37 22 27.6 sn rising 00.26 (i-i) 57774.46 20.12
PS17na 09 46 12.72 +60 21 47.8 sn rising 00.05 (i-i) 57774.46 20.20
PS17ra 09 32 04.34 +12 33 51.6 nt fading 00.30 (i-i) 57774.53 20.25
PS17lf 09 27 04.26 +54 23 46.9 sn fading 00.20 (i-i) 57774.46 20.29
PS17xn 09 56 26.51 +37 15 13.8 sn fading 00.31 (i-i) 57774.48 20.38
PS17pg 08 59 59.66 +57 50 26.4 sn fading 00.19 (i-i) 57774.40 20.39
PS17ol 10 06 47.59 +28 01 20.8 sn fading 00.02 (i-i) 57773.62 20.42
PS17ze 10 06 05.38 +53 04 45.1 sn fading 00.11 (i-i) 57774.47 20.42
PS17zj 10 11 15.00 +38 35 57.3 sn rising 00.09 (i-i) 57774.45 20.44
PS17xs 09 57 05.59 +21 58 29.3 sn rising 00.10 (i-i) 57774.54 20.46
PS17sz 09 40 39.32 +23 47 12.2 sn fading 00.06 (i-i) 57774.54 20.47
PS17ov 08 29 57.36 +66 14 08.8 nt rising 00.00 (i-i) 57774.46 20.48
PS17ql 09 29 15.03 +56 00 24.1 sn rising 00.20 (i-i) 57774.46 20.49
PS17vw 09 50 34.59 +25 47 26.9 sn rising 00.12 (i-i) 57774.53 20.49
PS17zf 10 07 01.98 +45 53 40.5 sn rising 00.04 (i-i) 57774.47 20.52
PS17rb 09 32 14.26 +65 26 46.1 sn fading 00.11 (i-i) 57774.45 20.53
PS17us 09 46 33.39 +46 22 07.7 sn rising 00.08 (i-i) 57774.47 20.54
PS17pr 09 21 46.06 +58 12 49.9 sn rising 00.00 (i-i) 57774.45 20.57
PS17sd 09 38 12.65 +16 03 29.6 sn rising 00.14 (i-i) 57774.54 20.58
PS17ss 09 39 30.92 +33 21 15.3 sn fading 00.01 (i-i) 57774.43 20.58
PS17sf 09 38 28.84 +39 46 01.3 sn fading 00.03 (i-i) 57774.46 20.58
PS17qo 09 29 51.26 +44 31 14.6 sn fading 00.08 (i-i) 57774.44 20.60
PS17se 09 38 27.88 +30 03 56.8 sn rising 00.01 (i-i) 57774.47 20.63
PS17xg 09 55 06.39 +27 07 19.6 sn rising 00.13 (i-i) 57774.54 20.63
PS17me 09 37 35.07 +25 35 58.6 sn fading 00.36 (i-i) 57774.54 20.63
PS17on 10 10 22.80 +48 01 28.1 sn rising 00.05 (i-i) 57774.42 20.65
PS17my 09 45 44.55 +20 47 29.5 nt fading 00.13 (i-i) 57774.54 20.67
PS17ui 09 45 33.30 +27 52 23.9 sn rising 00.08 (i-i) 57774.54 20.68
PS17nv 09 57 41.01 +17 49 33.4 orphan fading 00.12 (i-i) 57774.49 20.68
PS17rw 09 36 33.10 +26 22 07.1 sn fading 00.26 (i-i) 57774.54 20.71
PS17rj 09 34 39.14 +51 22 40.6 sn fading 00.07 (i-i) 57774.48 20.71
PS17xo 09 56 30.75 +31 25 47.2 sn fading 00.02 (i-i) 57774.50 20.72
PS17pn 09 18 26.20 +60 41 41.5 sn fading 00.05 (i-i) 57774.46 20.72
PS17vv 09 50 28.24 +29 41 50.3 nt rising 00.05 (i-i) 57774.54 20.72
PS17yi 09 59 48.09 +38 58 58.9 nt fading 00.07 (i-i) 57774.47 20.73
PS17qt 09 30 41.85 +46 20 36.4 sn rising 00.20 (i-i) 57774.45 20.73
PS17xm 09 56 09.82 +26 15 01.1 nt fading 00.12 (i-i) 57774.54 20.74
PS17wy 09 53 53.21 +50 31 08.8 sn fading 00.07 (i-i) 57774.46 20.75
PS17pv 09 25 07.35 +50 12 28.9 orphan fading 00.07 (i-i) 57774.47 20.75
PS17lh 09 29 15.24 +26 47 51.0 sn rising 00.00 (i-i) 57774.52 20.77
PS17xy 09 58 37.81 +29 07 33.6 sn rising 00.23 (i-i) 57774.55 20.77
PS17yq 10 02 49.53 +42 24 00.8 sn rising 00.09 (i-i) 57774.48 20.80
PS17wc 09 51 05.54 +29 22 46.3 sn fading 00.12 (i-i) 57774.54 20.80
PS17ti 09 42 19.84 +21 37 11.1 sn rising 00.02 (i-i) 57774.54 20.80
PS17yg 09 59 44.47 +24 12 03.4 sn fading 00.07 (i-i) 57774.53 20.80
PS17pa 08 38 05.32 +61 24 50.3 sn rising 00.07 (i-i) 57774.42 20.81
PS17pd 08 43 47.07 +64 31 31.4 sn rising 00.15 (i-i) 57774.46 20.81
PS17yj 10 00 16.53 +50 52 03.1 nt rising 00.02 (i-i) 57774.47 20.82
PS17vp 09 49 33.45 +48 49 32.0 sn fading 00.08 (i-i) 57774.47 20.82
PS17ry 09 36 46.35 +26 02 05.2 sn rising 00.02 (i-i) 57774.54 20.82
PS17qk 09 29 12.15 +25 49 06.4 orphan fading 00.20 (i-i) 57774.54 20.83
PS17ud 09 45 03.09 +22 50 09.9 sn rising 00.11 (i-i) 57774.54 20.86
PS17xx 09 58 27.56 +42 53 08.0 sn fading 00.10 (i-i) 57774.48 20.87
PS17qx 09 31 47.56 +12 59 46.8 nt fading 00.12 (i-i) 57774.53 20.87
PS17zb 10 05 56.86 +40 54 27.6 nt rising 00.11 (i-i) 57774.47 20.88
PS17vd 09 48 00.80 +30 06 42.5 sn fading 00.22 (i-i) 57774.51 20.89
PS17wr 09 53 16.55 +51 53 02.8 nt fading 00.09 (i-i) 57774.48 20.89
PS17vu 09 50 16.84 +34 56 19.0 sn rising 00.03 (i-i) 57774.46 20.90
PS17re 09 32 55.07 +52 12 49.5 sn rising 00.31 (i-i) 57774.46 20.92
PS17kv 09 24 01.40 +49 26 03.8 sn fading 00.04 (i-i) 57774.48 20.92
PS17ts 09 43 24.74 +18 08 49.9 sn fading 00.02 (i-i) 57774.54 20.93
PS17xh 09 55 13.67 +46 15 18.9 sn rising 00.10 (i-i) 57774.47 20.96
PS17kr 09 19 46.15 +59 28 37.2 sn fading 00.09 (i-i) 57774.43 20.97
PS17rd 09 32 27.06 +55 40 43.1 sn fading 00.02 (i-i) 57774.46 20.99
PS17vy 09 50 36.23 +22 04 33.8 sn rising 00.03 (i-i) 57774.54 21.01
PS17uo 09 46 11.91 +48 18 56.0 sn rising 00.22 (i-i) 57774.46 21.01
PS17wv 09 53 25.01 +32 39 23.8 sn rising 00.04 (i-i) 57774.47 21.01
PS17tm 09 43 10.54 +34 44 02.2 sn fading 00.08 (i-i) 57774.46 21.02
PS17ue 09 45 06.95 +17 42 19.0 sn rising 00.27 (i-i) 57774.54 21.03
PS17su 09 40 08.78 +23 00 53.1 sn rising 00.07 (i-i) 57774.54 21.04
PS17ku 09 23 44.48 +48 55 06.4 sn rising 00.10 (i-i) 57774.48 21.06
PS17vf 09 48 11.27 +18 20 40.8 nt rising 00.13 (i-i) 57774.54 21.08
PS17vg 09 48 15.51 +29 45 48.7 sn fading 00.03 (i-i) 57774.54 21.08
PS17vt 09 49 57.95 +19 38 47.0 sn rising 00.00 (i-i) 57774.54 21.09
PS17qp 09 30 30.25 +49 52 30.0 sn rising 00.03 (i-i) 57774.47 21.09
PS17rr 09 35 30.85 +16 59 18.1 sn rising 00.04 (i-i) 57774.55 21.10
PS17rz 09 36 57.19 +29 40 06.0 sn rising 00.22 (i-i) 57774.47 21.12
PS17pi 09 05 00.75 +61 01 10.6 sn rising 00.08 (i-i) 57774.45 21.14
PS17xp 09 56 36.86 +49 56 14.1 sn rising 00.12 (i-i) 57774.46 21.15
PS17ph 09 01 00.16 +57 53 49.4 sn rising 00.16 (i-i) 57774.40 21.16
PS17xf 09 55 02.96 +21 14 12.5 sn fading 00.08 (i-i) 57774.54 21.16
PS17vc 09 47 46.66 +41 17 18.0 nt rising 00.13 (i-i) 57774.46 21.18
PS17mp 09 41 52.10 +36 00 40.2 sn fading 00.14 (i-i) 57774.45 21.18
PS17ws 09 53 19.79 +42 26 50.8 sn fading 00.01 (i-i) 57774.46 21.19
PS17uu 09 47 01.91 +17 52 27.1 sn rising 00.03 (i-i) 57774.53 21.19
PS17uw 09 47 10.01 +16 13 51.5 nt rising 00.24 (i-i) 57774.56 21.20
PS17mf 09 37 43.60 +15 23 11.6 nt fading 00.19 (i-i) 57774.52 21.21
PS17lk 09 29 58.27 +15 11 58.5 orphan fading 00.02 (i-i) 57774.53 21.24
PS17xq 09 56 59.17 +27 31 23.2 sn rising 00.07 (i-i) 57774.54 21.24
PS17qq 09 30 35.36 +50 14 34.0 sn rising 00.12 (i-i) 57774.46 21.25
PS17rc 09 32 19.16 +47 03 38.3 orphan rising 00.06 (i-i) 57774.46 21.27
PS17yl 10 00 40.10 +40 39 21.9 sn rising 00.00 (i-i) 57774.47 21.27
PS17ro 09 35 07.03 +23 23 35.9 sn fading 00.00 (i-i) 57774.53 21.33
PS17tv 09 43 41.58 +27 07 59.2 sn fading 00.05 (i-i) 57774.54 21.35
PS17lp 09 31 42.79 +55 37 32.1 sn rising 00.25 (i-i) 57774.45 21.36
PS17mg 09 37 44.15 +17 46 23.5 sn rising 00.01 (i-i) 57774.54 21.37
PS17xk 09 56 08.33 +24 15 22.3 sn rising 00.01 (i-i) 57774.54 21.43
PS17sn 09 39 11.32 +15 24 28.7 nt rising 00.16 (i-i) 57774.52 21.44
PS17qs 09 30 38.38 +16 20 35.0 sn rising 00.12 (i-i) 57774.53 21.45
PS17um 09 46 02.11 +20 57 16.3 sn fading 00.01 (i-i) 57774.54 21.49
PS17qf 09 28 06.94 +16 23 30.8 sn rising 00.46 (i-i) 57774.53 21.50
PS17pk 09 13 47.60 +64 02 59.7 sn rising 00.48 (i-i) 57774.45 21.50
PS17vn 09 49 11.97 +19 17 06.7 sn rising 00.30 (i-i) 57774.54 21.59
PS17tq 09 43 15.46 +16 57 16.2 nt rising 00.12 (i-i) 57774.54 21.69
PS17sr 09 39 26.00 +23 46 04.8 sn rising 00.16 (i-i) 57774.54 21.84
GCN Circular 20515
Subject
LIGO/Virgo G270580: UL50 observations
Date
2017-01-24T14:36:21Z (9 years ago)
From
Klaas Wiersema at U of Leceister <kw113@leicester.ac.uk>
K. Wiersema (Leicester) reports on behalf of a larger collaboration:
We have performed V band tiled observations of LIGO/Virgo G270580 (LVC, GCN
20486) using the 0.5m telescope (UL50) of the University of Leicester,
between 19:00 UT on 20 jan 2017 and 00:30 on 21 jan 2017 (i.e. starting
6.5 hours after the LIGO event).
These consist of shallow, many-tile, mosaics of ~1 square degree centered
on some nearby galaxies from the GWGC catalogue, in particular UGC
03804 (RA=110.6,Dec=71.6), UGC 05295 (RA=142.2,Dec=42.8), and covering
galaxies near those positions. No credible transient candidates brighter
than V=17.0 were detected (but analysis is ongoing). In addition we
observed several other GWGC catalogue sources using smaller fields
of view (12x9 arc min) at a deeper limiting magnitude, e.g. NGC3009,
NGC3032, UGC03804. No transient candidates brighter than V=18.5 were
found near or in these galaxies. We do detect
MASTER OT J090737.22+611200.5 (Lipunov et al., GCN 20488), at
V~19.5 on 23:19 UT on 21 jan 2017.
GCN Circular 20513
Subject
LIGO/Virgo G270580: CALET Observations
Date
2017-01-24T12:55:12Z (9 years ago)
From
Takanori Sakamoto at Aoyama Gakuin U <tsakamoto@phys.aoyama.ac.jp>
Y. Kawakubo, A. Yoshida, T. Sakamoto, M. Moriyama, Y. Yamada (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (JAXA), I. Takahashi (IPMU),
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu,
T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena)
and the CALET collaboration:
The CALET Gamma-ray Burst Monitor (CGBM) was operating at the trigger time
of G270580 (GCN Circ. 20486). No CGBM on-board trigger occurred at the time
of the event. Based on the LIGO localization sky map (LIB_skymap.fits.gz),
the southern arc of the high probability area was in the field-of-view of CGBM.
The summed LIGO probabilities inside the HXM and the SGM field of view
are 24% and 33%.
Based on the analysis of the light curve data with 0.125 sec time resolution
from -60 sec to 60 sec from the trigger time, we found no significant excess
around the trigger time in either the HXM (7-1000 keV) or the SGM (0.1-20 MeV)
data.
The CALET Calorimeter (CAL) was operating in high energy trigger mode at the trigger
time of G270580. Using CAL data, we have searched for gamma-ray events above
10 GeV from -60 sec to +60 sec from the GW trigger time and found no candidates.
The summed LIGO probabilities inside the CAL field of view is ~4%.
GCN Circular 20512
Subject
LIGO/Virgo G270580: Pan-STARRS coverage and bright, rising transient PS17yt
Date
2017-01-24T12:37:51Z (9 years ago)
From
S. J. Smartt at Queens U Belfast <s.smartt@qub.ac.uk>
K. C. Chambers (IfA), K. W. Smith, D. R. Young, S. J. Smartt, (QUB)
J. Tonry, L. Denneau, A. Heinze, B. Stalder, H. Weiland (IfA),
C. W. Stubbs (Harvard), (QUB), , A. Rest (STScI),
T.-W. Chen (MPE), M. Coughlin (Harvard), M. E. Huber (IfA),
D. E. Wright (QUB), H. Flewelling, E. A. Magnier, A. S. B. Schultz,
C. Waters, R. J. Wainscoat (IfA)
The Pan-STARRS coverage plot has been loaded up to GraceDB.
A full list of transients will follow soon, however we highlight the following
rapidly rising transient for which spectroscopic follow-up is recommended.
PS17yt 10:03:57.96 +49:02:28.3 (J2000)
MJD i i_err
57776.4589778 19.16 0.06
57775.6452663 19.54 0.09
57774.4694054 19.71 0.03
It is 12.7 arcsec from the galaxy SDSS J100358.86+490219.3, at a redshift of z=0.067,
mu = 37.4, M_i ~ -18.2 (16 kpc projected distance).
GCN Circular 20509
Subject
LIGO/Virgo G270580/GW170120 : Asiago observations
Date
2017-01-23T13:09:13Z (9 years ago)
From
Andrea Rossi at INAF <a.rossi@iasfbo.inaf.it>
P. Ochner, L. Tomasella (INAF-OAPd), A. Rossi, E. Palazzi
(INAF-IASF Bo), E. Brocato (INAF-OAR), M. Branchesi
(Urbino University/INFN Firenze), E. Cappellaro (INAF-OAPd),
L.Amati (INAF-IASF Bo), L. A. Antonelli, (INAF-OAR),
P. Astone (INFN-Roma), S. Benetti (INAF-OAPd), S. Campana,
S. Covino, P. D'Avanzo, (INAF-OAB), V. D'Elia (INAF-ASDC),
F. Getman (INAF-OAC), G. Giuffrida (INAF-ASDC), A.Grado
(INAF-OAC), G.Greco (Urbino University/INFN Firenze),
L. Limatola (INAF-OAC), M. Lisi (INAF-OAR), S. Marinoni,
P. Marrese (INAF-ASDC), A. Melandri (INAF-OAB),
L. Nicastro (INAF-IASF Bo), A. Pastorello (INAF-OAPd),
E. Pian (SNS-Pisa), S. Piranomonte, L. Pulone (INAF-OAR),
F. Ricci (Sapienza University), G. Stratta
(Urbino University/INFN Firenze), G. Tagliaferri (INAF-OAB),
V. Testa (INAF-OAR), on behalf of GRAWITA report:
The transients PTSS-17dfc (GCN 20497) and PTSS-17dgm (GCN 20506) were
observed with the Asiago 1.22m Galileo telescope (DFA-UniPd; equipped
with B&C spectrograph, range 330-790 nm, resolution 0.7 nm) and with
1.82m Copernico telescope (INAF-OAPd; equipped with AFOSC, range 340-820
nm, resolution 1.4 nm), respectively.
PTSS-17dfc was observed on 2017-01-22.901 UT and the best match is with
Type Ia SNe near maximum light at a redshift ~0.022, which is
consistent with the spectroscopic redshift of the host galaxy provided
by SDSS-DR13 (z=0.024) .
PTSS-17dgm was observed on 2017-01-23.004 UT and the best match is also
with Type Ia SNe near maximum light at a redshift z~0.087, consistent
with the photometric redshift provided by SDSS-DR13 (z=0.069).
The classifications were performed using the GELATO (Harutyunyan et al.
2008, A&A, 488, 383) and SNID (Blondin and Tonry 2007, ApJ, 666, 1024)
tools.
The classification as Type Ia SNe near maximum light
makes these events likely not related to LIGO/Virgo G270580.
GCN Circular 20506
Subject
LIGO/Virgo G270580: A third optical transient from CNEOST
Date
2017-01-23T01:28:55Z (9 years ago)
From
Jinzhong Liu at Xinjiang Astronomical Observatory <liujinzh@xao.ac.cn>
Haibin Zhao (PMO/CAS), Dong Xu (NAO/CAS), Bin Li, Getu Zhaori, Hao Lu
(PMO/CAS), Hanjie Tan (CCU), Zhijian Xu, Wenxiong Li, Zesheng Yang,
Xiaofeng Wang (THU), Lifan Wang (PMO/CAS), Jujia Zhang (YNAO/CAS), Hao
Song (THU), Jinzhong Liu, Hubiao Niu, Yu Zhang, Xuan Zhang, Guangxin Pu,
Shuguo Ma, Taozhi Yang, Fangfang Song (XAO/CAS), Tianmeng Zhang, Xu Zhou
(NAO/CAS), Jirong Mao, Jinming Bai (YNAO/CAS), Huanxue Feng, Zipei
Zhu (NAO/CAS) report on behalf of the Gravitational Wave Follow-Up
Network by NAO-PMO-XAO-YNAO in China (GWFUNC):
Further analysis of the CNEOST observational data reported in our
previous GCN
20497 reveals a third optical transient, dubbed as PTSS-17dgm, at
coordinates
R.A. (J2000) = 09:30:36.58
Dec. (J2000) = +21:24:42.32
with m(r) = 18.94 +/- 0.08 at 18:24:25 UT on 2017-01-21. Again this
object may be a newly exploded supernova.
--
N: Jinzhong Liu, Dr.
O: Main building, 213
P: 150, Science 1-Street, Urumqi, Xinjiang 830011, China
T: 86 991 3689027
D: 2012-07-14
E: optics@xao.ac.cn
GCN Circular 20503
Subject
LIGO/Virgo G270580: ATLAS coverage and 4 optical transients
Date
2017-01-22T22:58:06Z (9 years ago)
From
S. J. Smartt at Queens U Belfast <s.smartt@qub.ac.uk>
K. W. Smith (QUB), J. Tonry, L. Denneau, A. Heinze, B. Stalder,
H. Weiland (IfA), C. W. Stubbs (Harvard), D. R. Young
(QUB), S. J. Smartt, (QUB), A. Rest (STScI), K. C. Chambers (IfA),
T.-W. Chen (MPE), M. Coughlin (Harvard), M. E. Huber (IfA),
D. E. Wright (QUB), H. Flewelling, E. A. Magnier, A. S. B. Schultz,
C. Waters, R. J. Wainscoat (IfA)
We report the following observations of the skymap for LIGO/Virgo
G270580 (discovered MJD = 57773.5215; LIGO Scientific Collaboration
and Virgo, GCN 20486) with the ATLAS telescope system. ATLAS
is a twin 0.5m telescope system on Haleakala and Mauna Loa (see Tonry
et al. ATel 8680 and Tonry 2011, PASP, 123, 58). The first unit is
operational on Haleakala and is robotically surveying the sky in two
filters cyan and orange (denoted c and o, all mags are in AB
system). More information is on http://www.fallingstar.com
ATLAS covered 1294 sq. deg. of the ~non-zero probability regions on
the nights MJD=577773,57774. We estimate that the coverage equates to
39.9% total all-sky probability of containing the source (from the
LALInference map; Veitch et al., PRD 91, 042003). A map of the ATLAS
footprints will be placed on GraceDB. The probability region was
covered in normal ATLAS survey mode, with typically 5 exposure per
footprint.
We detect the following transients. None are convincing counterparts
to the GW source for various reasons, but should be spectrally
classified. All four are in the Liverpool Telescope queue.
Name | RA (J2000) | Dec (J2000) | Disc. MJD | Disc. Date | Disc Mag | Notes
ATLAS17ajr | 12:28:58.69 | +31:39:37.7 | 57773.63 | 20170120.63 | 17.73 o | 1. AT2017mq
ATLAS17akl | 14:16:31.06 | +39:35:10.7 | 57766.67 | 20170113.67 | 17.72 o | 2. AT2017mf
ATLAS17akq | 13:16:05.81 | +36:04:19.9 | 57774.56 | 20170121.56 | 18.17 o | 3.
ATLAS17ajv | 10:26:42.36 | +36:40:49.9 | 57774.49 | 20170121.49 | 16.32 o | 4. PTSS-17dfc
1. ATLAS17ajr = AT2017mq. Host galaxy is z=0.03848. Close to, but
outside both the LIB cWB maps, hence released on the IAU Transient
name server. Some 3-sigma detections on forced photometry on
MJD=57761,
2. ATLAS17akl : 5 arcseconds from SN2006cb (and not related to that
SN). Amateur discovery on TNS (as AT2017mf). This is not within LIB,
but is within cWB map. However ATLAS detection on 57766.67, shows it
to have occurred 7 days before the GW detection.
3. ATLAS17akq : transient coincident with core of SDSS r=20.25 galaxy
(photo-z z=0.12). This is within the LIB map. But there is some
evidence of 3-4 sigma detections 8-12 days before this discovery.
4. ATLAS17ajv : we independently discovered this object which is
PTSS-17dfc (Zhao et al. GCN 20497). No detection (o < 18.3) on
MJD=57766. This is outside the LIB map, but within the cWB 90%
contours. Note we do not register objects publicly on the TNS if they
fall within the LIGO maps (and timeframe), hence we did not register
this one.
GCN Circular 20499
Subject
LIGO/Virgo G270580: Fermi-LAT search for a high-energy gamma-ray counterpart
Date
2017-01-22T20:36:18Z (9 years ago)
From
Daniel Kocevski at NASA/MSFC <dankocevski@gmail.com>
Daniel Kocevski (NASA/MSFC), Giacomo Vianello (Stanford), Nicola Omodei (Stanford) and Sara Buson (NASA/GSFC) report on behalf of the Fermi-LAT team:
We have searched data collected by the Fermi Large Area Telescope (LAT) for possible high-energy (E > 100 MeV) gamma-ray emission in spatial/temporal coincidence with the LIGO/Virgo trigger G270580.
The Fermi gamma-ray space telescope was passing through the South Atlantic Anomaly (SAA) at the time of the trigger (T0 = 2017-01-20 12:30:59.350). During SAA passages both the LAT and the Gamma-ray Burst Monitor (GBM) do not collect data due to the high charged particle background in this region. The LAT resumed data taking upon exiting the SAA at roughly T0 + 500 s. At that time the instantaneous coverage of the LIGO map was 18%, and we reached 80% cumulative coverage at T0 + 2.1 ks and 100% coverage within 8 ks from the trigger.
We performed a search for a transient counterpart within the 90% contour of the LIGO map in the time window from T0 to T0 + 10 ks. We found only one significant excess, corresponding to J1048.4+7144 (associated with FSRQ S5 1044+71) which has been in a high state since last December (ATel #9928). We also performed a search which adapted the time interval of the analysis to the exposure of each region of the sky. No significant candidate counterpart was found in neither of the two searches.
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 20497
Subject
LIGO/Virgo G270580: Two optical counterpart candidates from CNEOST
Date
2017-01-22T13:36:14Z (9 years ago)
From
Jinzhong Liu at Xinjiang Astronomical Observatory <liujinzh@xao.ac.cn>
Haibin Zhao (PMO/CAS), Dong Xu (NAO/CAS), Bin Li, Getu Zhaori, Hao Lu
(PMO/CAS), Hanjie Tan(CCU), Zhijian Xu, Wenxiong Li, Zesheng Yang,
Xiaofeng Wang(THU), Lifan Wang (PMO/CAS), Jujia Zhang(YNAO/CAS), Hao
Song (THU), Jinzhong Liu, Hubiao Niu, Yu Zhang, Xuan Zhang, Guangxin Pu,
Shuguo Ma, Taozhi Yang, Fangfang Song (XAO/CAS), Tianmeng Zhang, Xu Zhou
(NAO/CAS), Jirong Mao, Jinming Bai (YNAO/CAS), Huanxue Feng, Zipei
Zhu(NAO/CAS) report on behalf of the Gravitational Wave Follow-Up
Network by NAO-PMO-XAO-YNAO in China (GWFUNC):
We have performed tiled observations of LIGO/Virgo G270580 (LVC, GCN
20486) using the Nanshan One-meter Wide field Telescope (NOWT) in
Xinjiang, the 0.6/0.9-m Schmidt telescope at Xinglong, Hebei, and the
1-m Chinese Near Earth Object Survey Telescope (CNEOST) at Xuyi, Jiangsu.
CNEOST has a FOV of 3.0x3.0 deg^2, and covered more than 1200 square
degree from 10:19:45 UT to 21:46:16 UT on 2017-01-21 in the Sloan
r-filter. The coverage skymap is at
https://dl.dropboxusercontent.com/u/3665676/G270580/skymap20170121NEOST.jpg
The limit magnitude for this survey is of m(r)~21. Each field was
visited three times. Our vetting procedure gives rise to two GW optical
counterpart candidates, potentially supernovae:
Source 1 (dubbed as PTSS-17dfc):
RA (J2000) =10h26m42.37s
Dec(J2000) =+36:40:50.62
with m(r)=16.55 ��0.01 mag, and
Source 2 (dubbed as PTSS-17dfn)
RA(J2000) =09h59m44.71s
Dec(J2000)= +27:38:55.44
with m(r)=18.93 ��0.08 mag.
The NOWT has a FOV of 1.3 x 1.3 deg^2, and carried out observations in
the nights of 2017-01-20 and 2017-01-21. The liming magnitude is of
m(r)~19. The above two candidates are not covered by NOWT's surveys.
The Schmidt telescope has a FOV of 1.5x1.5 deg^2, and carried out
observations in the night of 2017-01-21. The liming magnitude is of
m(White)~19. The above two candidates are not covered by Schmidt's survey.
--
N: Jinzhong Liu, Dr.
O: Main building, 213
P: 150, Science 1-Street, Urumqi, Xinjiang 830011, China
T: 86 991 3689027
D: 2012-07-14
E: optics@xao.ac.cn
GCN Circular 20496
Subject
LIGO/Virgo G270580: INTEGRAL search of temporally coincident prompt hard X-ray
Date
2017-01-21T16:03:28Z (9 years ago)
From
Carlo Ferrigno at ISDC/INTEGRAL <carlo.ferrigno@unige.ch>
V. Savchenko and C. Ferrigno (ISDC, University of Geneva, CH)
on behalf of the INTEGRAL group: S. Mereghetti (IASF-Mi, Italy), E. Kuulkers (ESTEC/ESA, The Netherlands), A. Bazzano (IAPS-Roma, Italy), E. Bozzo, T. J.-L. Courvoisier (ISDC, University of Geneva, CH) S. Brandt (DTU - Denmark) R. Diehl (MPE-Garching, Germany) L. Hanlon (UCD, Ireland) P. Laurent (APC-CeA, France) A. Lutovinov (IKI, Russia) J.P. Roques (CESR, France) R. Sunyaev (IKI, Russia) P. Ubertini (IAPS-Roma, Italy)
We investigated serendipitous INTEGRAL observations carried out at the time of the LIGO/Virgo burst candidate G270580. The satellite was pointing at RA = 10:41:53 Dec=-56:35:09, away from the high-probability region, derived from the LIGO LALInference pipeline. The anti-coincidence shield of spectrometer on board of INTEGRAL (SPI/ACS) covered the full LIGO 90% confidence region and provided stringent constraints on the flux of possible electromagnetic counterparts in the energy range covered by INTEGRAL instruments.
We investigated the SPI-ACS light curve between -500 and +500 s from the trigger time (2017-01-20 12:30:59.35 UTC) on temporal scales from 0.1 to 100 s. We find a low-significance excess at the time of the trigger with a duration about 30s and an SNR of 2.8 sigma. If this excess were a gamma-ray transient, we need to assume a spectral shape to derive a fluence, since SPI-ACS has no spectral capability. For such a long transient, we use a typical Band model with indexes ���1, ���2.5, and E_peak ~ 300 keV: we estimate a fluence of 7 +/- 3e-7 erg/cm2 in the optimal direction for SPI-ACS sensitivity. The fluence estimate changes widely in the localisation region, reaching 4.7+/-1.9e-6 erg/cm2 in the least favourable direction; detailed maps will be made available in future publications.
In the preferred assumption that the above excess is a background fluctuation, we estimate typical 3-sigma upper limits of 4.4e-7 erg/cm2 for 10s duration assuming Band model parameters ���1, ���2.5 with E_ peak ~ 300 keV. To derive a limit for a typical short burst with 1 s duration, we use a harder cutoff power law spectrum with slope of ���0.5 and Epeak ~ 500 keV: we find a limiting fluence of 1.5e-7 erg/cm2 at 3 sigma c.l.. These limits assume an optimal perpendicular direction of the burst to the INTEGRAL pointing direction. However the extent of the region with optimal response depends on the possible source spectrum: we perform a detailed calculation only for a cuttoff powerlaw spectrum with slope of ���0.5 and Epeak ~ 500 keV: we estimate that 25% of the LIGO localisation probability region is covered with a range of sensitivity from optimal to 50% worse , while 10% of the area is covered with a substantially reduced SPI-ACS sensitivity, more than factor 3 lower than optimal.
Due to temporary technical problems at the time of the trigger, only SPI/ACS data could be used to search for gamma-ray counterparts with INTEGRAL. The SPI/ACS light curves, binned at 50 ms, are derived from 91 independent detectors with different lower energy thresholds (mainly between 50 keV and 150 keV) and an upper threshold at about 100 MeV. The ACS response varies substantially as a function of the source incident angle with an optimal effective area of about 6000 cm2 at 1 MeV.
GCN Circular 20495
Subject
LIGO/Virgo G270580: Swift-XRT sources
Date
2017-01-21T13:47:07Z (9 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans (U. Leicester), J.A. Kennea (PSU), S.D. Barthelmy
(NASA/GSFC), A.P. Beardmore (U. Leicester), A.A. Breeveld (UCL-MSSL),
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), N. Gehrels (NASA/GSFC), P. Giommi (ASI), C. Gronwall
(PSU), H.A. Krimm (CRESST/GSFC/USRA), N.P.M. Kuin (UCL-MSSL), A.Y. Lien
(GSFC/UMBC), D. Malesani (DARK/NBI), F.E. Marshall (NASA/GSFC), A.
Melandri (INAF-OAB), B. Mingo (U. Leicester), J.A. Nousek (PSU), S.R.
Oates (U. Warwick), P.T. O'Brien (U. Leicester), J.P. Osborne (U.
Leicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester), D.M.
Palmer (LANL), M. Perri (ASDC), J.L. Racusin (NASA/GSFC), 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 performed a series of 134 observations of galaxies (from the
GWGC catalogue) within the LVC error region for the GW trigger G270580,
using the 'LIB_skymap' GW localisation map. The observations currently
span from 19 ks to 40 ks after the LVC trigger, and cover 15.8 sq
degrees on the sky (corrected for overlaps). This covers 0.011 of the
probability in the LVC skymap, and 0.14 of the probability in the LVC
map after weighting by galaxies in the GWGC catalogue.
Unfortunately these observations result in significant heating of the
XRT detector, which produced an artificially elevated, inhomogeneous
background, which produced a number of spurious source detections which
were circulated as 'counterpart' notices, however only 2 of these
sources are deemed to be real upon manual inspection (we remind readers
that the counterpart notices are the result of a purely automated
process, human vetting is performed before these circulars are
produced).
We have detected 2 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 http://www.swift.ac.uk/ranks.php.
We have found:
* 0 sources of rank 1
* 0 sources of rank 2
* 0 sources of rank 3
* 2 sources of rank 4
For all flux conversions and comparisons with catalogues and upper
limits from other missions, we assumed a power-law spectrum with
NH=3e20 cm^2, and photon index (Gamma)=1.7
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 1:
=============
RA: 280.1625 ( = 18h 40m 39.00s) J2000
Dec: -77.1591 ( = -77d 09' 32.8") J2000
Error: +5.1 (arcsec, radius, 90% confidence).
Peak Rate: 2.1e-01 +/- 6.0e-02 ct/sec (0.3-10 keV)
Peak Flux: 8.9e-12 +/- 2.6e-12 erg cm^-2 s^-1 (0.3-10 keV)
Cat Source: 1SXPS J184038.0-770928 in the 1SXPS catalogue
Separation: 5.3" from the XRT source
Cat Rate: 2.5e-01 +/- 5.6e-03 ct/sec
Cat Flux: 1.1e-11 +/- 2.4e-13 erg cm^-2 s^-1 (0.3-10 keV)
so the source is not above the catalogued flux.
There is no evidence for fading.
There are 10 GWGC or 2MPZ galaxies within 200 kpc of the source.
A SIMBAD object `ATPMN J184038.5-770929' is 3.9" away.
There is 1 2MASS object within the source's 3-sigma error radius.
Source 4:
=============
RA: 110.1196 ( = 07h 20m 28.70s) J2000
Dec: +71.5431 ( = +71d 32' 35.2") J2000
Error: +5.7 (arcsec, radius, 90% confidence).
Peak Rate: 1.8e-01 +/- 7.3e-02 ct/sec (0.3-10 keV)
Peak Flux: 7.9e-12 +/- 3.1e-12 erg cm^-2 s^-1 (0.3-10 keV)
Cat Source: 1AXG J072025+7132 in the ASCA/ASCAGIS catalogue
Separation: 17.4" from the XRT source
Cat Rate: 2.4e-03 +/- 0.0e+00 ct/sec
Cat Flux: 0.0e+00 +/- 0.0e+00 erg cm^-2 s^-1 (0.3-10 keV)
so the source is not above the catalogued flux.
There is no evidence for fading.
There are 2 GWGC or 2MPZ galaxies within 200 kpc of the source.
This circular is an official product of the Swift team.
GCN Circular 20494
Subject
LIGO/Virgo G270580: Swift/BAT data search
Date
2017-01-21T11:15:23Z (9 years ago)
From
Takanori Sakamoto at Aoyama Gakuin U <tsakamoto@phys.aoyama.ac.jp>
S.D. Barthelmy (NASA/GSFC), A. Y. Lien (GSFC/UMBC), D.M. Palmer (LANL),
T. Sakamoto (AGU), A. A. Breeveld (MSSL-UCL), A.P. Beardmore (U. Leicester),
D.N. Burrows (PSU), S. Campana (INAF-OAB), S.B. Cenko (NASA/GSFC),
G. Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB),
V.D'Elia(ASDC), P.A. Evans (U. Leicester), N. Gehrels (NASA/GSFC),
P. Giommi (ASI), C. Gronwall (PSU), J. A. Kennea (PSU),
H.A. Krimm (CRESST/GSFC/USRA), N.P.M. Kuin (UCL-MSSL), D. Malesani (DARK/NBI),
F.E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), B. Mingo (U. Leicester),
J.A. Nousek (PSU), S.R. Oates (Uni. of Warwick), P.T. O'Brien (U. Leicester),
J.P. Osborne (U. Leicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester),
M. Perri (ASDC), J.L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU),
M.H. Siegel (PSU), G. Tagliaferri (INAF-OAB), 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
LIGO event G270580 (LIGO/VIRGO Collaboration GCN Circ. 20486),
where T0 is the LIGO trigger time (2017-01-20T12:31:00.350 UTC).
The BAT pointing position at T0 is
RA = 61.726 deg,
DEC = -71.914 deg,
ROLL = 229.416 deg.
The BAT Field of View (>0.1 partial coding) covers 17.98% of the integrated
LIGO localization probability.
The closest event data covers the time range from T0-138.839 to T0-0.747.
No sources with signal-to-noise ratio > 6 sigma are found in the event data.
Also, no significant detections (signal-to-noise ratio > 4 sigma) are found
in the BAT raw light curves with time bins of 64 ms, 1 s, and 1.6 s, respectively.
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 4-sigma upper limit in the 1-s binned light
curve corresponds to a flux upper limit (15-350 keV) of ~ 8.3 x 10^-8 erg/s/cm^2.
BAT retains decreased, but significant, sensitivity to rate increases for
gamma-ray events outside of its FOV. About 18.42% of the integrated LIGO
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 of those within the FOV.
GCN Circular 20492
Subject
LIGO/Virgo G270580: Mini-MegaTORTORA follow-up observations
Date
2017-01-21T01:33:33Z (9 years ago)
From
Sergey Karpov at Special Astrophysical Obs <karpov.sv@gmail.com>
S.Karpov, G.Beskin (SAO RAS and Kazan Federal University,
Russia), S.Bondar, E.Ivanov, E.Katkova, A.Perkov (OJS RPC PSI,
Russia), A.Biryukov (SAI MSU and Kazan Federal University,
Russia), V.Sasyuk (Kazan Federal University, Russia)
We observed the sky area corresponding to 49% probability of initial LIB
skymap for the advanced LIGO trigger G270580 with Mini-MegaTORTORA
nine-channel wide-field monitoring system (located at Special Astrophysical
Observatory near Russian 6-m telescope) between 2017-01-20 15:05:45 UT (2.6
hours since trigger) and 2017-01-20 19:31:28 UT (7.0 hours since trigger)
under varying weather condition.
Observations consisted of several pointings with 10 x 60 s unfiltered
exposures each in every channel, covering roughly 900 square degrees
simultaneously. Image of the total sky coverage is available at
http://mmt.favor2.info/scheduler/1436/lvc
The footprints of acquired images are uploaded to GraceDB.
Quick-look analysis did not reveal any transient brighter than V~13.5
magnitude in the data.
GCN Circular 20491
Subject
LIGO/Virgo G270580: Pan-STARRS and ATLAS observations of the skymap
Date
2017-01-21T00:52:25Z (9 years ago)
Edited On
2025-04-09T18:46:46Z (7 months ago)
From
S. J. Smartt at Queens U Belfast <s.smartt@qub.ac.uk>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Tyler Barna at University of Minnesota <tylerpbarna@gmail.com>
L. Denneau, K. C. Chambers, J. Tonry, M. E. Huber (IfA), D. R. Young (QUB),
C. W. Stubbs (Harvard), S. J. Smartt, K. W. Smith (QUB),
M. Coughlin (Harvard), T.-W. Chen (MPE), H. Flewelling, A. Heinze,
E. A. Magnier (IfA), A. Rest (STScI), B. Stalder (IfA), A. S. B. Schultz,
C. Waters, R. J. Wainscoat, H. Weiland (IfA), D. E. Wright (QUB),
The optical wide-field imaging systems ATLAS (see Tonry et al. GCN 20377)
and Pan-STARRS1 (see Chambers et al. GCN 20383 ) were both
observing part of the northern arc of G270580 of the LALInference map
for Burst reconstruction (Veitch et al. PRD, 91, 04200, as released in GCN 20486).
These observations were taken during the night of 2017-01-20 UT, just a
few hours after the GW source was detected.
These were mostly normal survey operations, with some pointed PS1
footprints in z and y filters close to the end of the night in Hawaii.
Not enough dark hours were available to allow the sky map to be targeted
and mapped out in full.
These (mostly) serendipitous footprints for the night of 2017-01-20 UT
have been uploaded in two plots on GraceDB.
ATLAS covered 209 sq deg. (all post-detection of G270580) which corresponds
to a 10% likelihood of covering the position of the source. They were taken
1.5 - 3hrs after G270580 detection, reaching AB mag of o~19 (orange filter)
Pan-STARRS1 covered an area of 95 sq. deg. of the likelihood arc
(pointings which lie on non-zero probability regions) equating to 5%
probability of containing the source. These were take approximately
2-4hrs after G270580 detection, reaching AB mag of i,z ~ 20 and y~19.
Analysis is ongoing and any transients will be report.
Weather permitting, we will target much larger regions beginning on
the night of 2017-01-21 UT.
GCN Circular 20490
Subject
LIGO/Virgo G270580: Observations of initial skymap by Project Mini-GWAC of SVOM
Date
2017-01-21T00:31:05Z (9 years ago)
Edited On
2024-11-16T16:14:02Z (a year ago)
From
Chao Wu at NAOC <wuchao.lamost@gmail.com>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
J.Y. Wei (NAOC), X.H. Han (NAOC), C. WU (NAOC), N. Leroy (LAL),S. Antier
(LAL), L.P. Xin (NAOC), X.M. Meng (NAOC), L. Huang (NAOC), Y. Xu(NAOC),
H.B. Cai (NAOC), J. Wang(NAOC), X.M. Lu (NAOC), Y.L. Qiu (NAOC), J.S. Deng
(NAOC), L. Cao (NAOC), S. Wang (NAOC), L. Jia (NAOC), S.C.Zou (NAOC), S.F.
Liu (NAOC), Q.C. Feng (NAOC), H.L. Li (NAOC), D.W. Xu (NAOC),Y.J. Xiao
(NAOC), W.L. Dong (NAOC), Y.T. Zheng (NAOC), E.W.Liang (GXU),
X.G.Wang(GXU), Y.G. Yang (HBNU), B. Cordier (CEA), S.N. Zhang (NAOC),
D. Dornic (CPPM) , B.B. Wu (IHEP), Jean-Luc Atteia (IRAP), D. Götz (CEA),C.
Lachaud (APC) on behalf of the SVOM Gravitational Astronomy group report:
We observed about 3600 square degree (9 sky regions) of the skymap of the
advanced LIGO trigger G270580, with SVOM/Mini-GWAC, at Xinglong Observatory
of NAOC equipped
with U9000 camera (FOV~400 square degree/camera). SVOM/Mini-GWAC comprises
12 wide field angle cameras (aperture=7cm), working with unfiltered band.
The observations
are operated in time-series mode, taking one exposure in 15 seconds (10s
exposure + 5s readout). The limit magnitude is ~12 mag in R band. We
estimate a 66.9% prior probability that these 9 regions contain the true
location of the source.
The coordinates of the 9 regions and observation time are list following:
start-obs(UTC) end-obs(UTC) Ra Dec Camera_ID
2017-01-20 12:50:28.3 2017-01-20 14:15:07.6 09:10:23.301 +29:35:57.71 C1
2017-01-20 12:50:28.3 2017-01-20 22:14:58.6 09:12:26.259 +10:35:26.10 C2
2017-01-20 13:50:51.4 2017-01-20 19:47:59.1 06:36:32.060 +69:30:22.27 C5
2017-01-20 13:50:51.4 2017-01-20 19:48:01.2 06:42:03.137 +50:31:15.23 C6
2017-01-20 14:15:35.4 2017-01-20 22:19:45.5 09:17:48.639 +69:36:41.75 C1
2017-01-20 14:15:35.4 2017-01-20 22:19:48.5 09:21:16.884 +50:34:54.73 C2
2017-01-20 14:16:01.4 2017-01-20 21:24:39.2 09:08:57.610 +30:01:54.06 C3
2017-01-20 14:16:01.4 2017-01-20 21:25:03.9 09:13:11.448 +09:57:30.75 C4
2017-01-20 19:49:04.7 2017-01-20 21:36:13.2 10:34:34.322 +29:30:16.35 C5
2017-01-20 19:49:27.9 2017-01-20 22:19:41.5 10:37:18.165 +10:30:56.78 C6
2017-01-20 21:32:19.1 2017-01-20 22:19:53.1 13:29:12.042 +10:00:17.26
The first image was taken ~20 minutes after the event trigger. No any
significant transient is found in our online pipeline. The image analysis
is ongoing in detailed processing with our offline pipeline.
GCN Circular 20489
Subject
LIGO/Virgo G270580: AGILE MCAL and Super-AGILE Observations
Date
2017-01-20T21:57:23Z (9 years ago)
From
Francesco Verrecchia at ASDC, INAF-OAR <verrecchia@asdc.asi.it>
F. Lucarelli, F. Verrecchia (ASDC and INAF/OAR), A. Ursi (INAF/IAPS), Y.
Evangelista (INAF/IAPS), M. Tavani (INAF/IAPS, and Univ. Roma Tor
Vergata), F. Fuschino (INAF/IASF-Bo), I. Donnarumma (INAF/IAPS), G.
Minervini (INAF/IAPS), M. Marisaldi (INAF/IASF-Bo and Bergen University),
A. Bulgarelli, V. Fioretti (INAF/IASF-Bo), C. Pittori (ASDC and
INAF/OAR), G. Piano, P. Munar-Adrover, A. Argan (INAF/IAPS), M. Cardillo
(INAF/OA-Arcetri and INAF/IAPS), A. Giuliani (INAF/IASF-Mi), M. Pilia, A.
Trois (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 G270580 (GCN #20486) at
T0 = 2017-01-20 12:30:59.350 UTC, the analysis of the AGILE data near T0
shows that the onboard data acquisition was interrupted due to the
passage over the South Atlantic Anomaly (SAA), which covered the time
interval (T0 - 280; T0 + 216) s.
A preliminary AGILE-GW data processing identified two Mini-Calorimeter
(MCAL) data acquisitions before and after the SAA passage. The first
data interval (following an internal trigger) started at T1 = 12:26:14
UTC, and ended at T2 = 12:26:22 UTC. The second one, started at
T3 = 12:36:16 UTC, and ended at T4 = 12:36:24 UTC. An analysis of these
data does not reveal any significant transient event in the energy range
0.4-100 MeV. A preliminary three-sigma upper limit (UL) is obtained for
a 1 s integration time at different celestial positions within the
accessible G270580 localization region, for a typical fluence of 8.8e-7
erg cm^-2, in the 400-10000 keV energy range assuming a spectral photon
index of 1.4.
The Super-Agile (SA) detector had a partial coverage of the G270580
localization region at T0. No significant detection was obtained in the
SA light curve (20-60 keV), for a stable background within +/- 100 s
from T0. SA is an X-ray coded mask instrument with 40x40 deg field of
view at half-sensitivity.
Furthermore, a search in the AGILE anticoincidence (AC) and GRID
ratemeters data did not produce any significant detection.
The GRID large-FoV (2.5 sr) imaging instrument had no exposure near T0
of the G270580 localization region. The GRID data analysis in the energy
range 30 MeV - 10 GeV is in progress, and the results will be reported
in a following GCN.
GCN Circular 20487
Subject
LIGO/Virgo G270580 ANTARES search
Date
2017-01-20T19:55:50Z (9 years ago)
From
Damien Dornic at CPPM/CNRS <dornic@cppm.in2p3.fr>
M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (APC/Universite Paris Diderot), D. Dornic (CPPM/CNRS), A. Kouchner (APC/Universite Paris Diderot), 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 G270580 event using the initial LIGO skyprobcc_cWB probability map at event time. The ANTARES visibility at the time of the alert together with the 90% contour of the probability map are shown in: https://www.cppm.in2p3.fr/~dornic/events/GW270580.png (gwantares/ANT@GW). Considering the location probability provided by the LIGO collaboration, there is a 50% chance that the GW emitter was in the ANTARES field of view.
ANTARES, being installed in the Mediterranean Deep Sea, is the largest neutrino detector in the Northern Hemisphere. It is primarily sensitive to astrophysical neutrinos in the TeV-PeV energy range. At 10 TeV, the median angular resolution for muon neutrinos is below 0.5 degrees. In the range 1-100 TeV, ANTARES has the best sensitivity to a large fraction of the Southern sky.
No up-going muon neutrino candidate events were recorded within the 90% contour during a +/- 500s time-window centered on the G270580 event time. The expected number of atmospheric background events in the 90% contour region visible by ANTARES is ~6e-3 in the +/- 500s time window. An extended search during +/- 1 hour gives no up-going neutrino coincidence.
An estimate of the upper limit on the associated neutrino fluence will be sent in a subsequent circular.
GCN Circular 20486
Subject
LIGO/Virgo G270580: Identification of a GW Burst Candidate
Date
2017-01-20T14:38:03Z (9 years ago)
From
Gergely Dalya at Eotvos U <dalyag@caesar.elte.hu>
The LIGO Scientific Collaboration and Virgo report:
The online CWB Burst analysis identified a candidate with GraceDB ID
G270580 during processing of data from LIGO Hanford Observatory (H1)
and LIGO Livingston Observatory (L1) at 2017-01-20 12:30:59.350 UTC
(GPS time: 1168950677.350).
G270580 is an event of interest because its false alarm rate, as
determined by preliminary analysis, is 1.6e-07 Hz (about one in 2.4
months). The event's properties can be found at this URL:
https://gracedb.ligo.org/events/G270580
This event candidate does *not* have a chirp signature, and thus does
not suggest a compact binary merger. The initial GCN Notice for this
candidate (ivorn=ivo://nasa.gsfc.gcn/LVC#G270580-6-Initial)
erroneously included "ProbHasNS" and "ProbHasRemnant" values due to a
software bug; we regret any confusion that may have caused. (These
probabilities are only calculated for CBC event candidates.)
Two sky maps have been calculated and can be retrieved from the
GraceDB event page. LIB_skymap.fits.gz, a rapid localization using
LALInference (Veitch et al., PRD 91, 042003) for Burst reconstruction,
is the preferred sky map at this time. The 50% credible region spans
about 600 deg2 and the 90% region about 3100 deg2. The CWB skymap has
a consistent shape but is broader.
We will provide updated information about this event candidate as it
becomes available.