LIGO/Virgo S191222n
GCN Circular 26868
Subject
LIGO/Virgo S191222n: AstroSat CZTI upper limits
Date
2020-01-24T05:14:59Z (6 years ago)
From
Varun Bhalerao at Indian Inst of Tech <varunb@iitb.ac.in>
V. Shenoy (IITB), Aarthy E. (PRL), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao (TIFR), S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
We have carried a search for X-ray candidates in Astrosat CZTI data in a 100 sec window around the trigger time of the BBH Merger event S191222n (UTC 2019-12-22 03:35:37, GraceDB event). We use the LALInference.fits.gz,0 map (LVC GCN 26572; https://gracedb.ligo.org/api/superevents/S191222n/files/LALInference.fits.gz,0) for our analysis. CZTI is a coded aperture mask instrument that has considerable effective area for about 29% of the entire sky, but is also sensitive to brighter transients from the entire sky. At the time of the BBH merger, Astrosat's nominal pointing is RA,DEC = 12:36:27.1, 62:17:02.9 (189.1129,62.2841), which is ~112 deg away from the maximum probability location. At the time of the BBH merger event, the Earth-satellite-transient angle corresponding to maximum probability location is ~117 deg and hence is not occulted by Earth in satellite's frame. In a time interval of 100 sec around the event, the region of the localisation map which is not occulted by Earth in the satellite's frame has a cumulative probability of 0.89 (89%).
CZTI data were de-trended to remove orbit-wise background variation. We then searched data from the four independent, identical quadrants to look for coincident spikes in the count rates. Searches were undertaken by binning the data in 0.1s, 1s, and 10s respectively. Statistical fluctuations in background count rates were estimated by using data from 10 (+-5) neighbouring orbits. We selected confidence levels such that the probability of a false trigger in a 1000 sec window is 10^-4. We do not find any evidence for any hard X-ray transient in this window, in the CZTI energy range of 20-200 keV.
We use a detailed mass model of the satellite to calculate the direction-dependent instrument response for points in the visible sky. We then assume the source is modelled as a power law with photon index alpha = -1, and convert our count rate upper limits to direction-dependent flux limits. We obtain the following upper limits for source flux in the 20-200 keV band by taking a probability weighted mean over the visible sky:
0.1 s: flux limit= 9.37e-06 ergs/cm^2/s; fluence limit = 9.37e-07 ergs/cm^2
1.0 s: flux limit= 2.99e-06 ergs/cm^2/s; fluence limit = 2.99e-06 ergs/cm^2
10.0 s: flux limit= 3.86e-07 ergs/cm^2/s; fluence limit = 3.86e-06 ergs/cm^2
CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.
GCN Circular 26836
Subject
LIGO/Virgo S191222n: Upper limits from Konus-Wind observations
Date
2020-01-21T08:49:08Z (6 years ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
A. Ridnaia, S. Golenetskii, R.Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline,
on behalf of the Konus-Wind team, report:
Konus-Wind (KW) was observing the whole sky at the time of the
LIGO/Virgo event S191222n (2019-12-22 03:35:37.119 UTC, hereafter T0;
LIGO/Virgo Collaboration GCN Circ. 26543).
No triggered KW GRBs happened ~6 hours before and ~5 days
after T0. The closest waiting-mode GRB was observed ~1.5 hours after T0.
Using waiting-mode data within the interval T0 +/- 100 s,
we found no significant (> 5 sigma) excess over the background
in both KW detectors on temporal scales from 2.944 s to 100 s.
We estimate an upper limit (90% conf.) on the 20 - 1500 keV fluence
to 8.3x10^-7 erg/cm^2 for a burst lasting less than 2.944 s and having a
typical KW short GRB spectrum (an exponentially cut off power law with
alpha =-0.5 and Ep=500 keV). For a typical long GRB spectrum (the Band
function with alpha=-1, beta=-2.5, and Ep=300 keV), the corresponding
limiting peak flux is 2.6x10^-7 erg/cm^2/s (20 - 1500 keV, 2.944 s scale).
All the quoted values are preliminary.
GCN Circular 26602
Subject
LIGO/Virgo S191222n: No transient candidates in CALET observations
Date
2019-12-28T06:20:43Z (6 years ago)
From
Yuta Kawakubo at Louisiana State U./CALET <kawakubo1@lsu.edu>
V. Pal'shin, A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (Waseda U), Y. Shimizu,
T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:
The CALET Gamma-ray Burst Monitor (CGBM) was operating at the trigger
time of S191222n T0 = 2019-12-22 03:35:37.119 UT (The LIGO Scientific
Collaboration and Virgo Collaboration, GCN Circ. 26543, 26572).
No CGBM on-board trigger occurred around the event time. Based on the
LVC high probability localization region, the summed LIGO probabilities
inside the CGBM HXM (7 - 3000 keV) and SGM (40 keV - 28 MeV) fields
of view are 6 % and 30 %, respectively (and 60 % credible region of the
updated localization map was above the horizon). The HXM and SGM fields
of view were centered at RA = 337.7 deg, Dec = +4.6 deg and
RA = 330.3 deg, Dec = -2.1 deg at T0, respectively.
Based on the analysis of the light curve data with 0.125 sec time
resolution from T0-60 sec to T0+60 sec, we found no significant excess
(signal-to-noise ratio >= 7) around the trigger time in either the HXM or
the SGM data.
The CALET Calorimeter (CAL) was operating in the low energy trigger
mode at the trigger time of S191222n. Using the CAL data, we have
searched for gamma-ray events in the 1-10 GeV band from -60 sec
to +60 sec from the GW trigger time and found no candidates. There
is no significant overlap with the LVC high probability localization
region at T0+-60 sec. The CAL FOV was centered at RA = 330.3 deg,
Dec = -2.1 deg at T0.
GCN Circular 26575
Subject
LIGO/Virgo S191222n : No significant candidates in FRAM-TAROT-GRANDMA observations
Date
2019-12-24T14:25:27Z (6 years ago)
From
Jean-Gregoire Ducoin at LAL <ducoin@lal.in2p3.fr>
J.-G. Ducoin (LAL), N. Leroy (LAL), W. Lin (THU), X. Zhang (THU),
M. Masek (FZU), S. Karpov (FZU), M. Prouza (FZU), M. Boer (Artemis),
N. Christensen (Artemis), L. Eymar (Artemis), A. Klotz (IRAP),
K. Noysena (Artemis,IRAP), S. Antier (APC), A. Coleiro (APC),
D. Corre (LAL), M. Coughlin (Caltech), D. Coward (OzGrav-UWA),
B. Gendre (OzGrav-UWA), P. Hello (LAL), D. A. Kann (HETH/IAA-CSIC),
N. Kochiashvili (Iliauni), C. Lachaud (APC), C. Thoene (HETH/IAA-CSIC),
D. Turpin (AIM-CEA), X. Wang (THU)
Report on behalf of the FRAM, TAROT and GRANDMA collaborations.
We performed tiled observations of LIGO/Virgo S191222n event with the
FRAM-Auger, FRAM-CTA-N, TAROT-Calern (TCA), TAROT-Chili (TCH), TAROT-
Reunion (TRE) telescopes.
FRAM-Auger is located at Pierre Auger Observatory. FRAM-CTA-N is
located at Observatorio del Roque de los Muchachos. TCA is located at
Calern site at the Cote d'Azur observatory. TCH is located at La Silla
ESO observatory (LaS/ESO). TRE is located at Les Makes astronomical
observatory.
The following table shows for each telescope: the delay in minutes
from the trigger, which filter is used, the field of view of the
telescope in degrees and the typical limiting magnitude (AB mag) for a
given exposure in seconds (s).
+-------------+---------+----------+-------------+------------+
| Telescope | Delay | Filter | f.o.v. | Limiting |
| | [min] | | [deg] | Mag. |
|-------------+---------+----------+-------------+------------|
| FRAM-Auger | 23 | R | 1.0 x 1.0 | 18.0 (60s) |
| FRAM-CTA-N | 41 | R | 0.45 x 0.45 | 17.0 (90s) |
| TCA | 40 | Clear | 1.9 x 1.9 | 18.0 (60s) |
| TCH | 177 | Clear | 1.9 x 1.9 | 18.0 (60s) |
| TRE | 748 | Clear | 4.2 x 4.2 | 17.0 (60s) |
+-------------+---------+----------+-------------+------------+
We performed the following joint tiled observations [1] :
+-------------+------------+------------+---------+---------+---------+
| Telescope | TStart | TEnd | RA | DEC | Proba |
| | [UTC] | [UTC] | [deg] | [deg] | [%] |
|-------------+------------+------------+---------+---------+---------|
| FRAM-Auger | 2019-12-22 | 2019-12-22 | 237.073 | -63.730 | 0.1 |
| | 03:58:21 | 04:02:48 | | | |
| FRAM-Auger | 2019-12-22 | 2019-12-22 | 224.348 | -55.946 | 0.2 |
| | 05:10:40 | 05:15:06 | | | |
| FRAM-Auger | 2019-12-22 | 2019-12-22 | 226.087 | -55.946 | 0.2 |
| | 05:15:41 | 05:20:08 | | | |
| FRAM-Auger | 2019-12-22 | 2019-12-22 | 226.337 | -56.919 | 0.2 |
| | 05:20:42 | 05:25:09 | | | |
| FRAM-Auger | 2019-12-22 | 2019-12-22 | 228.119 | -56.919 | 0.1 |
| | 05:25:44 | 05:30:11 | | | |
| FRAM-Auger | 2019-12-22 | 2019-12-22 | 228.426 | -57.892 | 0.1 |
| | 05:30:45 | 05:35:12 | | | |
| FRAM-Auger | 2019-12-22 | 2019-12-22 | 221.284 | -54.000 | 0.2 |
| | 05:35:48 | 06:20:32 | | | |
| FRAM-Auger | 2019-12-22 | 2019-12-22 | 226.599 | -57.892 | 0.2 |
| | 08:08:35 | 08:13:02 | | | |
| FRAM-Auger | 2019-12-22 | 2019-12-22 | 221.166 | -53.027 | 0.2 |
| | 08:13:37 | 08:18:04 | | | |
| FRAM-Auger | 2019-12-22 | 2019-12-22 | 222.609 | -55.946 | 0.2 |
| | 08:18:40 | 08:23:07 | | | |
| FRAM-Auger | 2019-12-22 | 2019-12-22 | 222.780 | -53.027 | 0.1 |
| | 08:23:42 | 08:28:09 | | | |
| FRAM-Auger | 2019-12-22 | 2019-12-22 | 223.099 | -54.973 | 0.2 |
| | 08:28:44 | 08:33:11 | | | |
| FRAM-Auger | 2019-12-22 | 2019-12-23 | 219.552 | -53.027 | 0.2 |
| | 08:33:46 | 07:43:53 | | | |
| FRAM-Auger | 2019-12-23 | 2019-12-23 | 222.936 | -54.000 | 0.1 |
| | 07:44:29 | 07:48:56 | | | |
| FRAM-Auger | 2019-12-23 | 2019-12-23 | 224.789 | -54.973 | 0.1 |
| | 07:49:30 | 07:53:57 | | | |
| FRAM-Auger | 2019-12-23 | 2019-12-23 | 224.772 | -57.892 | 0.2 |
| | 07:54:32 | 07:58:59 | | | |
| FRAM-Auger | 2019-12-23 | 2019-12-23 | 221.408 | -54.973 | 0.2 |
| | 07:59:33 | 08:03:59 | | | |
| FRAM-Auger | 2019-12-23 | 2019-12-23 | 230.254 | -57.892 | 0.1 |
| | 08:04:36 | 08:09:03 | | | |
| FRAM-Auger | 2019-12-23 | 2019-12-23 | 228.063 | -58.865 | 0.1 |
| | 08:09:37 | 08:14:04 | | | |
| FRAM-Auger | 2019-12-23 | 2019-12-23 | 224.587 | -54.000 | 0.1 |
| | 08:14:39 | 08:19:06 | | | |
| ----- | ----- | ----- | ----- | ----- | ----- |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 45.307 | 32.992 | <0.1 |
| | 04:15:46 | 04:19:52 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 54.254 | 41.829 | <0.1 |
| | 04:20:09 | 04:24:16 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 48.439 | 35.501 | <0.1 |
| | 04:24:32 | 04:28:38 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 46.931 | 33.866 | <0.1 |
| | 04:28:52 | 04:32:58 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 47.412 | 34.740 | <0.1 |
| | 04:33:11 | 04:37:17 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 52.308 | 40.419 | <0.1 |
| | 04:37:34 | 04:41:40 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 52.280 | 37.361 | <0.1 |
| | 04:41:55 | 04:46:01 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 50.884 | 36.050 | <0.1 |
| | 04:46:15 | 04:50:21 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 49.825 | 35.176 | <0.1 |
| | 04:50:38 | 04:54:43 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 55.629 | 40.419 | <0.1 |
| | 04:55:00 | 04:59:06 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 50.345 | 38.672 | <0.1 |
| | 04:59:21 | 05:03:27 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 49.481 | 37.897 | <0.1 |
| | 05:03:41 | 05:07:47 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 44.563 | 32.992 | <0.1 |
| | 05:08:04 | 05:12:10 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 47.368 | 35.501 | <0.1 |
| | 05:12:26 | 05:16:32 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 51.574 | 38.672 | <0.1 |
| | 05:16:47 | 05:20:53 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 50.703 | 37.897 | <0.1 |
| | 05:21:12 | 05:25:18 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 54.944 | 40.419 | <0.1 |
| | 05:25:34 | 05:29:40 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 56.314 | 40.419 | <0.1 |
| | 05:29:59 | 05:34:05 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 48.615 | 36.050 | <0.1 |
| | 05:34:21 | 05:38:27 | | | |
| FRAM-CTA-N | 2019-12-22 | 2019-12-22 | 54.025 | 40.419 | <0.1 |
| | 05:38:48 | 05:42:54 | | | |
| ----- | ----- | ----- | ----- | ----- | ----- |
| TCA | 2019-12-22 | 2019-12-22 | 54.104 | 40.847 | 0.1 |
| | 04:15:33 | 04:21:53 | | | |
| TCA | 2019-12-22 | 2019-12-22 | 51.688 | 39.897 | 0.1 |
| | 04:22:19 | 04:28:38 | | | |
| TCA | 2019-12-22 | 2019-12-22 | 55.571 | 42.703 | 0.1 |
| | 04:35:22 | 04:41:42 | | | |
| TCA | 2019-12-22 | 2019-12-22 | 62.227 | 44.558 | 0.2 |
| | 05:25:04 | 05:27:04 | | | |
| ----- | ----- | ----- | ----- | ----- | ----- |
| TCH | 2019-12-22 | 2019-12-23 | 207.660 | -38.141 | 0.6 |
| | 06:32:03 | 07:38:25 | | | |
| TCH | 2019-12-22 | 2019-12-24 | 206.988 | -36.323 | 0.5 |
| | 06:38:52 | 08:45:15 | | | |
| TCH | 2019-12-22 | 2019-12-24 | 210.064 | -41.777 | 0.6 |
| | 06:51:41 | 06:27:58 | | | |
| TCH | 2019-12-22 | 2019-12-23 | 220.611 | -52.686 | 0.7 |
| | 07:00:29 | 08:04:39 | | | |
| TCH | 2019-12-22 | 2019-12-24 | 211.373 | -43.595 | 0.7 |
| | 07:11:17 | 06:47:24 | | | |
| TCH | 2019-12-22 | 2019-12-22 | 212.530 | -41.777 | 0.3 |
| | 07:30:51 | 07:37:09 | | | |
| TCH | 2019-12-22 | 2019-12-23 | 223.959 | -54.505 | 0.5 |
| | 07:37:22 | 08:43:16 | | | |
| TCH | 2019-12-22 | 2019-12-24 | 217.535 | -50.868 | 0.7 |
| | 07:49:57 | 07:26:16 | | | |
| TCH | 2019-12-22 | 2019-12-24 | 224.283 | -56.323 | 0.6 |
| | 07:56:44 | 07:33:01 | | | |
| TCH | 2019-12-22 | 2019-12-24 | 214.785 | -47.232 | 0.8 |
| | 08:36:11 | 08:12:30 | | | |
| TCH | 2019-12-23 | 2019-12-24 | 205.394 | -34.980 | 0.6 |
| | 07:13:00 | 08:17:07 | | | |
| TCH | 2019-12-23 | 2019-12-23 | 217.491 | -47.232 | 0.4 |
| | 08:17:32 | 08:23:50 | | | |
| TCH | 2019-12-23 | 2019-12-24 | 217.512 | -49.050 | 0.6 |
| | 08:24:03 | 05:59:49 | | | |
| TCH | 2019-12-23 | 2019-12-24 | 208.367 | -39.959 | 0.7 |
| | 08:43:28 | 06:21:27 | | | |
| TCH | 2019-12-24 | 2019-12-24 | 214.863 | -45.414 | 0.5 |
| | 06:34:35 | 06:36:35 | | | |
| TCH | 2019-12-24 | 2019-12-24 | 213.908 | -43.595 | 0.3 |
| | 06:54:01 | 07:00:20 | | | |
| ----- | ----- | ----- | ----- | ----- | ----- |
| TRE | 2019-12-22 | 2019-12-22 | 51.429 | 36.818 | 1.1 |
| | 16:03:26 | 16:09:42 | | | |
| TRE | 2019-12-22 | 2019-12-22 | 43.784 | 32.727 | 0.6 |
| | 16:16:10 | 16:22:32 | | | |
| TRE | 2019-12-22 | 2019-12-23 | 300.000 | -73.636 | 0.7 |
| | 16:41:47 | 17:47:59 | | | |
| TRE | 2019-12-22 | 2019-12-23 | 42.078 | 28.636 | 0.9 |
| | 20:50:51 | 16:57:05 | | | |
| TRE | 2019-12-22 | 2019-12-22 | 199.459 | -32.727 | 1.7 |
| | 21:28:54 | 21:33:01 | | | |
| TRE | 2019-12-22 | 2019-12-23 | 204.324 | -32.727 | 2.2 |
| | 23:55:45 | 00:02:07 | | | |
| TRE | 2019-12-23 | 2019-12-23 | 192.857 | -16.364 | 1.2 |
| | 21:27:12 | 21:31:20 | | | |
| TRE | 2019-12-23 | 2019-12-23 | 188.372 | -12.273 | 1.2 |
| | 22:09:48 | 22:16:04 | | | |
| TRE | 2019-12-23 | 2019-12-23 | 192.558 | -12.273 | 0.6 |
| | 22:22:32 | 22:28:48 | | | |
+-------------+------------+------------+---------+---------+---------+
TStart and TEnd refers respectively to the time of the first and last
exposure for a given tile. Observations are not necessarily continuous
in this interval.
The Probability refers to the 2D spatial probability of the GW skymap
enclosed in a given tile.
These observations cover about 21.2% of the cumulative probability of
the LALInference skymap created on 2019-12-22 22:16:22
(UTC).
The coverage map is available at:
https://grandma-owncloud.lal.in2p3.fr/index.php/s/XgtMhPRxcyL09gR/
download?path=%2F&files=GRANDMA_S191222n_1577195108.png
No significant transient candidates were found during our low latency
analysis [2,3].
GRANDMA (Global Rapid Advanced Network Devoted to the Multi-messenger
Addicts) is a network of robotic telescopes connected all over the
world with both photometry and spectrometry capabilities for Time-
domain Astronomy [2](https://grandma.lal.in2p3.fr/).
Details on the different telescopes are available on the GRANDMA web
pages.
[1] M. W Coughlin et al., MNRAS 2019, https://doi.org/10.1093/mnras/stz2485
[2] S. Antier et al., MNRAS 2019, https://doi.org/10.1093/mnras/stz3142
[3] K. Noysena et al., ApJ 2019, arXiv:1910.0277
GCN Circular 26572
Subject
LIGO/Virgo S191222n: Updated Sky Localization
Date
2019-12-24T07:01:34Z (6 years ago)
From
Daniel Holz at U of Chicago <qrs@uchicago.edu>
The LIGO Scientific Collaboration and the Virgo Collaboration report:
We have conducted further analysis of the LIGO Hanford Observatory
(H1) and LIGO Livingston Observatory (L1) data around the time of the
compact binary merger (CBC) candidate S191222n (GCN Circular 26543).
Parameter estimation has been performed using LALInference [1] and
a new sky map, LALInference.fits.gz,0, distributed via GCN Notice, is
available for retrieval from the GraceDB event page:
https://gracedb.ligo.org/superevents/S191222n
The preferred sky map at this time is LALInference.fits.gz,0. For the
LALInference.fits.gz,0 sky map, the 90% credible region is 1850 deg2.
Marginalized over the whole sky, the a posteriori luminosity distance
estimate is 2518 +/- 679 Mpc (a posteriori mean +/- standard
deviation).
For further information about analysis methodology and the contents of
this alert, refer to the LIGO/Virgo Public Alerts User Guide
<https://emfollow.docs.ligo.org/userguide/>.
GCN Circular 26571
Subject
LIGO/Virgo S191222n: no counterpart candidate in SVOM/GWAC observations
Date
2019-12-24T02:40:16Z (6 years ago)
From
Xuhui Han at NAOC/SVOM <hxh@nao.cas.cn>
C. Wu (NAOC), M. Dennefeld (IAP/CNRS/SU) , X. Wang (GXU),
R. Duque (CNRS/IAP), S.S. Sun (GXU)
report on behalf of the SVOM Multi Messenger Astronomy and GWAC teams
(http://www.svom.fr/en/svom-mma-and-gwac-team <http://www.svom.fr/en/svom-mma-and-gwac-team>):
We observed 37 150-sq. deg sky regions to cover the skymap of the
advanced LIGO/Virgo trigger S191222n (GCN # 26543), with SVOM/GWAC,
at Xinglong Observatory. SVOM/GWAC is equipped with two sets of
wide angle cameras:
- FFOV cameras (FOV~900 square degrees/camera, aperture = 3.5 cm),
- JFOV cameras (FOV~150 square degrees/camera, aperture = 18 cm).
SVOM/GWAC currently comprises 4 FFOV cameras and 16 JFOV cameras,
working in the unfiltered band. The observations are operated in
time-series mode, taking one exposure every 25 seconds
(20s exposure + 5s readout). The observed and processed regions enclosed
an estimated 36.9% of the probability of the advanced LIGO/Virgo skymap.
Images were taken between ~8.8 minutes and ~16.63 hours after the GW trigger
time. The coordinates of the 37 sky regions observed after the trigger and
their observation times and covered probability are listed below:
Id Ra Dec start (UTC) end (UTC) Cov. Cam.
1 07:24:00.24 53:02:52.80 2019-12-22 12:32:11 2019-12-22 12:59:41 0.021 JFOV
2 05:50:52.75 52:05:58.20 2019-12-22 12:17:05 2019-12-22 12:23:10 0.029 JFOV
3 07:30:30.00 48:26:49.56 2019-12-22 13:37:33 2019-12-22 14:39:54 0.017 JFOV
4 08:31:26.64 36:09:36.36 2019-12-22 13:41:12 2019-12-22 14:39:54 0.001 JFOV
5 08:26:42.72 47:40:49.80 2019-12-22 13:28:55 2019-12-22 13:49:59 0.017 JFOV
6 08:57:33.12 48:28:44.40 2019-12-22 14:40:49 2019-12-22 15:08:43 0.014 JFOV
7 09:58:28.80 36:10:45.48 2019-12-22 14:40:49 2019-12-22 15:08:44 0.010 JFOV
8 09:03:17.76 36:28:34.68 2019-12-22 14:40:49 2019-12-22 15:08:44 0.005 JFOV
9 09:53:40.32 47:42:14.40 2019-12-22 14:56:46 2019-12-22 15:41:54 0.004 JFOV
10 08:46:46.08 35:05:22.92 2019-12-22 14:41:22 2019-12-22 15:41:54 0.001 JFOV
11 11:07:09.36 14:33:39.96 2019-12-22 17:28:48 2019-12-22 17:56:42 0.008 JFOV
12 11:52:22.32 02:14:49.49 2019-12-22 17:28:48 2019-12-22 17:56:43 0.024 JFOV
13 11:43:29.28 13:47:45.24 2019-12-22 17:28:23 2019-12-22 17:56:20 0.011 JFOV
14 11:43:07.44 01:33:46.40 2019-12-22 17:28:23 2019-12-22 17:55:56 0.017 JFOV
15 13:05:04.80 -14:43:42.60 2019-12-22 19:55:37 2019-12-22 20:13:24 0.059 JFOV
16 12:19:09.84 -14:28:44.04 2019-12-22 19:45:30 2019-12-22 20:13:24 0.029 JFOV
17 12:54:54.96 -3:11:46.03 2019-12-22 19:45:37 2019-12-22 20:13:35 0.015 JFOV
18 01:16:50.26 13:21:14.40 2019-12-22 10:55:10 2019-12-22 10:56:23 0.002 JFOV
19 01:31:43.61 -2:38:38.15 2019-12-22 12:00:30 2019-12-22 12:28:24 0.011 JFOV
20 01:31:11.11 -14:41:56.76 2019-12-22 12:00:30 2019-12-22 12:28:25 0.003 JFOV
21 01:15:33.36 -15:41:16.80 2019-12-22 12:32:50 2019-12-22 13:00:47 0.002 JFOV
22 02:22:18.02 19:03:32.04 2019-12-22 11:36:09 2019-12-22 11:56:47 0.039 JFOV
23 01:35:19.34 19:18:38.16 2019-12-22 11:51:07 2019-12-22 11:56:47 0.004 JFOV
24 01:20:10.46 18:12:47.16 2019-12-22 11:34:30 2019-12-22 11:57:11 0.001 JFOV
25 02:48:12.86 31:22:33.96 2019-12-22 10:12:47 2019-12-22 10:39:04 0.047 JFOV
26 03:43:25.08 30:52:54.84 2019-12-22 10:26:10 2019-12-22 10:28:04 0.012 JFOV
27 02:50:44.57 19:20:33.36 2019-12-22 10:19:15 2019-12-22 10:39:04 0.021 JFOV
28 02:33:21.58 30:19:24.96 2019-12-22 10:10:30 2019-12-22 10:38:27 0.037 JFOV
29 03:28:18.70 18:23:05.64 2019-12-22 10:16:10 2019-12-22 10:38:27 0.022 JFOV
30 02:35:25.70 18:14:51.72 2019-12-22 10:11:43 2019-12-22 10:38:27 0.032 JFOV
31 05:29:11.35 53:00:20.88 2019-12-22 13:03:21 2019-12-22 13:31:15 0.032 JFOV
32 04:15:03.79 53:17:51.36 2019-12-22 13:03:45 2019-12-22 13:23:58 0.019 JFOV
33 04:36:43.78 48:22:15.60 2019-12-22 11:11:19 2019-12-22 11:25:29 0.039 JFOV
34 04:42:32.40 36:22:20.28 2019-12-22 11:14:09 2019-12-22 11:20:13 0.002 JFOV
35 04:20:09.24 47:15:37.80 2019-12-22 11:16:02 2019-12-22 11:27:22 0.042 JFOV
36 05:32:53.42 47:36:12.96 2019-12-22 11:10:51 2019-12-22 11:25:51 0.024 JFOV
37 04:26:06.91 35:13:31.80 2019-12-22 10:57:54 2019-12-22 11:24:14 0.003 JFOV
The sky coverage map is available at:
http://cmm.svom.cn/gwpub/O3/S191222n/S191222n.png <http://cmm.svom.cn/gwpub/O3/S191222n/S191222n.png>
(user:svomo3 pwd:gwo3).
Weather conditions were clear during the observations. An average 3-sigma
limiting magnitude of 16 mag in the R band was obtained in the single
frames. No credible new source was detected by our online pipeline during
follow-up observations. A more detailed image analysis including
co-addition is ongoing with our offline pipeline to search for transient
candidates.
GCN Circular 26557
Subject
LIGO/Virgo S191222n: no counterpart candidates in the Swift/BAT observations
Date
2019-12-22T16:57:53Z (6 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
T. Sakamoto (AGU), S. D. Barthelmy (NASA/GSFC),
A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL)
A. P. Beardmore (U. Leicester), M. G. Bernardini (INAF-OAB),
A. A. Breeveld (MSSL-UCL), D. N. Burrows (PSU),
S. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC),
G. Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA),
P. D'Avanzo (INAF-OAB), V. D'Elia (ASI-ASDC), S. Emery (UCL-MSSL),
P. A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU),
D. Hartmann (Clemson U.), J. A. Kennea (PSU),
N. Klingler (PSU), H. A. Krimm (NSF),
N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), J. A. Nousek (PSU),
S. R. Oates (Uni. of Warwick), P. T. O'Brien (U. Leicester),
J. P. Osborne (U. Leicester), C. Pagani (U. Leicester),
K. L. Page (U.Leicester), M. J. Page (UCL-MSSL), M. Perri (ASDC),
J. L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU),
M. H. Siegel (PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (Toronto),
E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team:
We report the search results in the BAT data within T0 +/- 100 s of the
LVC event S191222n (LIGO/VIRGO Collaboration GCN Circ. 26543),
where T0 is the LVC trigger time (2019-12-22T03:35:37.119 UTC).
The center of the BAT field of view (FOV) at T0 is
RA = 243.449 deg,
DEC = 65.736 deg,
and the roll angle is 151.289 deg.
The BAT FOV (>10% partial coding) covers 0.04% of the integrated
LVC localization probability, and 0.04% of the galaxy convolved
probability (Evans et al. 2016). Note that the sensitivity in the BAT FOV
changes with the partial coding fraction. Please see the BAT FOV figure
in the summary page (link below) for the specific location of the LVC
region relative to the BAT FOV.
Within T0 +/- 100 s, no significant astrophysical detections
(signal-to-noise ratio >~ 5 sigma) are found in the BAT raw light curves
with time bins of 64 ms, 1 s, and 1.6 s. The dip and pulse seen in the
light curves around T0+190 s is due to on-board calibration process
during spacecraft slews.
Assuming an on-axis (100% coded) short GRB with a typical spectrum in the
BAT energy range (i.e., a simple power-law model with a power-law index
of -1.32, Lien & Sakamoto et al. 2016), the 5-sigma upper limit in the
1-s binned light curve corresponds to a flux upper limit (15-350 keV)
of ~ 7.80 x 10^-8 erg/s/cm^2. Assuming a luminosity of ~ 2 x 10^47 erg/s
(similar to GW170817)and an average Epeak of ~ 400 keV for short GRBs
(Bhat et al. 2016), this flux upper limit corresponds to a distance
of ~ 81.37 Mpc.
No event data are available within T0 +/- 100 s at this time.
BAT retains decreased, but significant, sensitivity to rate increases for
gamma-ray events outside of its FOV. About 86.58% of the integrated LVC
localization probability was outside of the BAT FOV but above the
Earth's limb from Swift's location, and the corresponding flux upper limits
for this region are within roughly an order of magnitude higher than those
within the FOV.
The results of the BAT analysis are available at
https://swift.gsfc.nasa.gov/results/BATbursts/team_web/S191222n/web/source_public.html
GCN Circular 26556
Subject
LIGO/Virgo S191222n: No counterpart candidates in Fermi-LAT observations
Date
2019-12-22T15:26:14Z (6 years ago)
From
Elena Moretti at IFAE,Barcelona <moretti@ifae.es>
*LIGO/Virgo S191222n: No counterpart candidates in Fermi-LAT observations *
E. Moretti (IFAE, Barcelona), M. Crnogorcevic (Univ. of Maryland &
NASA/GSFC), F. Longo (UniTS and INFN, Trieste) and M. Axelsson (KTH &
Stockholm Univ.) report on behalf of the Fermi-LAT Collaboration:
We have searched data collected by the Fermi Large Area Telescope (LAT) on
Dec 22, 2019, for possible high-energy (E > 100 MeV) gamma-ray emission
in spatial/temporal coincidence with the LIGO/Virgo trigger S191222n (GCN
26543).
We define "instantaneous coverage" as the integral over the region of the
LIGO probability map that is within the LAT field of view at a given time,
and "cumulative coverage" as the integral of the instantaneous coverage
over time.
The Fermi Gamma-ray Space Telescope was passing through the South
Atlantic Anomaly (SAA) at the time of the trigger (T0
= 2019-12-22 03:35:37.118 UTC). 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 taking data upon
exiting the SAA at roughly T0 + 1ks. At that time the instantaneous
coverage was 55% of the LIGO probability map, and reached cumulative
coverage of 90% after ~5 ks. The remaining area was not observed within 10
ks following the trigger time of the event.
We performed a search for a transient counterpart within the observed
region of the 90% contour of LIGO map in a fixed time window from T0 + 1ks
to T0 + 10 ks. No significant new sources are found.
We also performed a search which adapted the time interval of the analysis
to the exposure of each region of the sky, and no additional excesses were
found.
Energy flux upper bounds for the fixed time interval between 100 MeV and 1
GeV for this search vary between 1.4e-10 and 5.7e-08 [erg/cm^2/s].
The Fermi-LAT point of contact for this event is Milena Crnogorcevic (
mcrnogor@astro.umd.edu).
The Fermi-LAT is a pair conversion telescope designed to cover the energy
band from 20 MeV to greater than 300 GeV. It is the product of an
international collaboration between NASA and DOE in the U.S. and many
scientific institutions across France, Italy, Japan and Sweden.
--
*Institut de F��sica d'Altes Energies (IFAE) Universitat Aut��noma de
Barcelona, Edifici Cn 08193 Bellaterra (Barcelona), Spain Tel:+34 931 70 27
10Av��s - Aviso - Legal Notice - (LOPD) - http://legal.ifae.es
<http://legal.ifae.es>*
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Aviso - Legal Notice - (LOPD) - http://legal.ifae.es
<http://legal.ifae.es/>
GCN Circular 26554
Subject
LIGO/Virgo S191222n: not observable by Fermi-GBM
Date
2019-12-22T14:27:01Z (6 years ago)
From
Rachel Hamburg at UAH <rkh0007@uah.edu>
R. Hamburg (UAH) reports on behalf of the Fermi-GBM Team and the
GBM-LIGO/Virgo group:
At the time of S191222n (GCN 26543