LIGO/Virgo S191222n
GCN Circular 26541
Subject
LIGO/Virgo S191222n: Global MASTER-Net observations report
Date
2019-12-22T03:56:19Z (5 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin,
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov, D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),
H.Levato
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),
D. Buckley
(South African Astronomical Observatory),
O.A. Gres, N.M. Budnev, O.Ershova
(Irkutsk State University, API),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko
(Blagoveschensk Educational State University)
MASTER-IAC robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) started inspect of the LIGO/Virgo S191222n errorbox 60 sec after notice time and 360 sec after trigger time at 2019-12-22 03:41:37 UT, with upper limit up to 18.9 mag. The observations began at zenith distance = 68 deg. The sun altitude is -53.7 deg.
The galactic latitude b = 18 deg., longitude l = 318 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/ligo_1.php?id=11107
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
395 | 2019-12-22 03:41:37 | MASTER-IAC | (03h 16m 18.78s , +34d 18m 17.0s) | P| | 70 | 18.2 |
395 | 2019-12-22 03:41:37 | MASTER-IAC | (03h 15m 29.37s , +34d 22m 21.5s) | P- | 70 | 18.0 |
532 | 2019-12-22 03:43:44 | MASTER-IAC | (03h 15m 26.66s , +34d 22m 25.2s) | P- | 90 | 18.2 |
532 | 2019-12-22 03:43:44 | MASTER-IAC | (03h 16m 16.28s , +34d 18m 23.3s) | P| | 90 | 18.5 |
713 | 2019-12-22 03:46:24 | MASTER-IAC | (03h 16m 18.86s , +34d 18m 26.0s) | P| | 130 | 18.9 |
713 | 2019-12-22 03:46:24 | MASTER-IAC | (03h 15m 29.02s , +34d 22m 27.1s) | P- | 130 | 18.5 |
The observation and reduction will continue.
The message may be cited.
GCN Circular 26542
Subject
LIGO/Virgo S191222n: Upper limits from IceCube neutrino searches
Date
2019-12-22T04:09:01Z (5 years ago)
From
Alex Pizzuto at ICECUBE/U of Wisconsin <pizzuto@wisc.edu>
IceCube Collaboration (http://icecube.wisc.edu/) reports:
Searches [1,2] for track-like muon neutrino events detected by IceCube
consistent with the sky localization of gravitational-wave candidate S191222n
in a time range of 1000 seconds [3] centered on the alert event time
(2019-12-22 03:27:17.119 UTC to 2019-12-22 03:43:57.119 UTC) have been performed.
During this time period IceCube was collecting good quality data.
No significant track-like events are found in spatial coincidence of
S191222n calculated from the map circulated in the 1-Preliminary notice.
IceCube's sensitivity assuming an E^-2 spectrum (E^2 dN/dE) to neutrino
point sources within the locations spanned by the 90% spatial containment
of S191222n ranges from 0.029 to 1.028 GeV cm^-2 in a 1000 second
time window.
The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector
operating at the geographic South Pole, Antarctica. The IceCube realtime
alert point of contact can be reached at roc@icecube.wisc.edu<mailto:roc@icecube.wisc.edu>
[1] Bartos et al. arXiv:1810.11467 (2018) and Countryman et al.arXiv:1901.05486 (2019)
[2] PoS(ICRC2019)918 and Braun et al., Astroparticle Physics 29, 299 (2008)
[3] Baret et al., Astroparticle Physics 35, 1 (2011)
GCN Circular 26543
Subject
LIGO/Virgo S191222n: Identification of a GW compact binary merger candidate
Date
2019-12-22T04:14:57Z (5 years ago)
From
Sarah Antier at APC <antier@apc.in2p3.fr>
The LIGO Scientific Collaboration and the Virgo Collaboration report:
We identified the compact binary merger candidate S191222n during
real-time processing of data from LIGO Hanford Observatory (H1) and
LIGO Livingston Observatory (L1) at 2019-12-22 03:35:37.119 UTC (GPS
time: 1261020955.119). The candidate was found by the GstLAL [1],
SPIIR [2], and CWB [3] analysis pipelines.
S191222n is an event of interest because its false alarm rate, as
estimated by the online analysis, is 6.5e-12 Hz, or about one in 5e3
years. The event's properties can be found at this URL:
https://gracedb.ligo.org/superevents/S191222n
The classification of the GW signal, in order of descending
probability, is BBH (>99%), Terrestrial (<1%), BNS (<1%), MassGap
(<1%), or NSBH (<1%).
Assuming the candidate is astrophysical in origin, the probability
that the lighter compact object has a mass < 3 solar masses (HasNS) is
<1%. Using the masses and spins inferred from the signal, the
probability of matter outside the final compact object (HasRemnant) is
<1%.
Two sky maps are available at this time and can be retrieved from the
GraceDB event page:
��* bayestar.fits.gz,0, an initial localization generated by BAYESTAR
[4], distributed via GCN notice about 3 minutes after the candidate
event time.
��* bayestar.fits.gz,1, an initial localization generated by BAYESTAR
[4], distributed via GCN notice about 9 minutes after the candidate
event time.
The preferred sky map at this time is bayestar.fits.gz,1. For the
bayestar.fits.gz,1 sky map, the 90% credible region is 2324 deg2.
Marginalized over the whole sky, the a posteriori luminosity distance
estimate is 868 +/- 265 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/>.
��[1] Messick et al. PRD 95, 042001 (2017)
��[2] Qi Chu, PhD Thesis, The University of Western Australia (2017)
��[3] Klimenko et al. PRD 93, 042004 (2016)
��[4] Singer & Price PRD 93, 024013 (2016)
GCN Circular 26544
Subject
LIGO/Virgo S191222n: No counterpart candidates in HAWC observations
Date
2019-12-22T04:27:54Z (5 years ago)
From
Antonio Galvan at Inst.de Astronomia,UNAM <agalvan@astro.unam.mx>
The HAWC Collaboration (https://www.hawc-observatory.org) reports:
The HAWC Collaboration performed a follow-up of the gravitational wave
trigger S191222n (GCN #26543). At the time of the trigger the HAWC
local zenith was oriented towards (RA, Dec) = (46.7 deg, 18.9 deg).
21% of the GW candidate sky location probability fell within our
observable field of view (0-45 deg zenith angle).
We performed a search for a short timescale emission using 6 sliding
time windows (dt = 0.3s, 1s, 3s, 10s, 30s and 100s), shifted forward
in time by 20% of their width. We searched the 95% probability
containment area in a timescale-dependent time period, from t0-5dt to
t0+10dt, where t0 is the time of the GW trigger.
No significant gamma-ray detection above the background was observed.
The sensitivity of this analysis is greatly dependent on zenith angle,
ranging from 3.6 deg to 45.0 deg for the area searched in this
analysis. The 5sigma detection sensitivity to a 1s (100s) burst in the
80-800GeV energy range goes from 1.2e-06 erg/cm^2 to 1.1e-04 erg/cm^2
(6.6e-06 erg/cm^2 to 5.0e-04 erg/cm^2), depending on the zenith
angle.
HAWC is a TeV gamma ray water Cherenkov array located in the state of
Puebla, Mexico. It is sensitive to the energy range ~0.1-100TeV, and
monitors 2/3 of the sky every day with an instantaneous field-of-view
of ~2 sr.
GCN Circular 26545
Subject
LIGO/Virgo S191222n: INTEGRAL was inactive at the time of the event
Date
2019-12-22T05:07:41Z (5 years ago)
From
Alexander Lutovinov at Space Research Inst.,IKI <aal@iki.rssi.ru>
Alexander Lutovinov (IKI, Moscow),
Sandro Mereghetti (INAF IASF-Milano, Italy),
V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland)
J. Rodi (IAPS-Roma, Italy)
A. Coleiro (APC, France)
on behalf of the INTEGRAL multi-messenger collaboration:
https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration
The INTEGRAL spacecraft has a highly elliptical orbit and the
instruments are not acquiring science data during perigee passage,
every 2.6 days to prevent radiation-induced damages. Unfortunately, at
the time of the S191222n (2019-12-22 03:35:37, GCN26543) the spacecraft
was preparing to the start the observations after the perigee passage
between the orbits number 2173 and 2174 and no scientific instrument
data are available between 2019-12-21T18:45:19 and
2019-12-22T10:44:07.
GCN Circular 26546
Subject
LIGO/Virgo S191222n: Coverage and upper limits from MAXI/GSC observations
Date
2019-12-22T05:22:48Z (5 years ago)
From
Motoko Serino at RIKEN/MAXI <motoko@crab.riken.jp>
N. Kawai (Tokyo Tech), H. Negoro (Nihon U.),
S. Sugita, M. Serino (AGU),
M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi, R. Takagi (Nihon U.),
T. Mihara, C. Guo, Y. Zhou, T. Tamagawa, M. Matsuoka (RIKEN),
T. Sakamoto, H. Nishida, A. Yoshida (AGU),
Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, T. Sato (Chuo U.),
M. Shidatsu (Ehime U.), M. Oeda, K. Shiraishi (Tokyo Tech),
S. Nakahira, Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, R. Shimomukai, M. Tominaga (JAXA),
Y. Ueda, A. Tanimoto, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.),
H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.),
M. Yamauchi, S. Iwahori, Y. Kurihara, K. Kurogi, K. Miike (Miyazaki U.),
T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU), M. Sugizaki (NAOC)
report on behalf of the MAXI team:
We examined MAXI/GSC all-sky X-ray images (2-20 keV)
after the LVC trigger S191222n at 2019-12-22 03:35:37.119 UTC (GCN 26543).
At the trigger time of S191222n, the high-voltage of MAXI/GSC was on.
The instantaneous field of view of GSC at the GW trigger time covered 1% of the 90% credible region
of the bayestar sky map, in which we found no significant new X-ray source.
The first one-orbit (92 min) scan observation with GSC after the event covered 84%
of the 90% credible region of the bayestar skymap from 03:35:37 to 04:37:24 UTC (T0+0 to T0+3707 sec).
No significant new source was found in the region in the one-orbit scan observation.
A typical 1-sigma averaged upper limit obtained in one scan observation
is 20 mCrab at 2-20 keV.
If you require information about X-ray flux by MAXI/GSC at specific coordinates,
please contact the submitter of this circular by email.
GCN Circular 26547
Subject
LIGO/Virgo S191222n: upper limits from AGILE/MCAL observations
Date
2019-12-22T07:54:54Z (5 years ago)
From
Francesco Longo at U of Trieste,INFN Trieste <franzlongo1969@gmail.com>
F. Longo (UniTS and INFN Trieste), M. Pilia (INAF/OA-Cagliari),
M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata),
M. Cardillo, C. Casentini, G. Piano, A. Ursi (INAF/IAPS),
F.Lucarelli, C. Pittori, F. Verrecchia (SSDC, and INAF/OAR),
A.Bulgarelli, V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna),
report on behalf of the AGILE Team:
In response to the LIGO/Virgo GW event S191222n at T0 = 2019-12-22
03:35:37.119 (UT), a preliminary analysis of the AGILE minicalorimeter
(MCAL) triggered data found no event candidates within a time
interval covering -/+ 15 sec from the LIGO/Virgo T0.
At the T0, about 60% of the S191222n 90% c.l. localization region was
accessible to the AGILE MCAL.Three-sigma upper limits (ULs) are
obtained for a 1 s integration time at different celestial positions
within the accessible S191222n localization region, from a minimum of
1.4E-06 erg cm^-2 to a maximum of 6.5E-06 erg cm^-2 (assuming as
spectral model a single power law with photon index 1.5).
The AGILE-MCAL detector is a CsI detector with a 4 pi FoV, sensitive
in the energy range 0.4-100 MeV. Additional analysis of AGILE data is
in progress.
GCN Circular 26548
Subject
LIGO/Virgo S191222n: upper limits from AGILE-GRID observations
Date
2019-12-22T08:17:30Z (5 years ago)
From
Francesco Longo at U of Trieste,INFN Trieste <franzlongo1969@gmail.com>
F. Longo (UniTS and INFN Trieste), M. Pilia (INAF/OA-Cagliari),
M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata),
M. Cardillo, C. Casentini, G. Piano, A. Ursi (INAF/IAPS),
F. Lucarelli, C. Pittori, F. Verrecchia (SSDC, and INAF/OAR),
A. Bulgarelli, V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna),
report on behalf of the AGILE Team:
In response to the LIGO-Virgo GW event S191222n at T0 = 2019-12-22
03:35:37.119 (UT) a preliminary analysis of the AGILE exposure at T0
shows that the Gamma-Ray Imaging Detector (GRID) exposure covered
the 38% of the 90% c.l. localization region (LR) (19% of the LR was
occulted by Earth).
We performed an analysis of the GRID data in the energy range 50 MeV -
10 GeV on T0, where good exposure of the S191222n 90% c.l. LR
was available.
No candidate gamma-ray transient was detected.
The following preliminary GRID values of 3-sigma upper limit (UL) are obtained:
from 7.8e-07 to 4e-06 erg cm^-2 s^-1, with exposure of about 38% of the LR
over the time interval ( T0 -2s ; T0 + 2s );
from 3.2e-07 to 1.6e-06 erg cm^-2 s^-1, with exposure of about 38% of
the LR over the time interval ( T0s ; T0 + 10s );
from 3.4e-08 to 3.5e-06 erg cm^-2 s^-1, with exposure of about 42% of
the LR over the time interval ( T0s ; T0 + 100s );
These measurements were obtained with AGILE observing a large portion of
the sky in spinning mode. Additional analysis of AGILE data is in progress.
GCN Circular 26550
Subject
LIGO/Virgo S191222n : no neutrino counterpart candidate in ANTARES search
Date
2019-12-22T10:03:26Z (5 years ago)
From
Antoine Kouchner at ANTARES Collaboration <kouchner@apc.in2p3.fr>
M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (APC/Universite de Paris), M. Colomer (APC/Universite de Paris), D. Dornic (CPPM/CNRS), A. Kouchner (APC/Universite de Paris), T. Pradier (IPHC/Universite de Strasbourg) report on behalf of the ANTARES Collaboration:
Using on-line data from the ANTARES detector, we have performed a follow-up analysis of the
recently reported LIGO/Virgo S191222n event using the 90% contour of the Preliminary GW_SKYMAP probability
map provided by the GW interferometers (GCN#26543). The ANTARES visibility at the time of the
alert, together with the 50% and 90% contours of the probability map are shown at http://antares.in2p3.fr/GW/S191222n_Preliminary.png <http://antares.in2p3.fr/GW/S191222n_Preliminary.png>.
Considering the location probability provided by the LIGO/Virgo collaborations, there is a
53.1% chance that the GW emitter was in the ANTARES **upgoing** field of view at the time of
the alert.
No up-going muon neutrino candidate events were recorded in the ANTARES sky during a
+/-500s time-window centered on the time 2019-12-22 03:35:37 and in the 90% contour of the S191222n
event. The expected number of atmospheric background events in the region visible by ANTARES is
5.21e-04 in the +/- 500s time window. An extended search during +/- 1 hour gives no
up-going muon neutrino coincidence. The expected number of atmospheric background events in the
region visible by ANTARES is 3.75e-03 in this larger time window.
ANTARES is the largest undersea neutrino detector, installed in the Mediterranean Sea, and it is
primarily sensitive to neutrinos in the TeV-PeV energy range. At 10 TeV, the median angular
resolution for muon neutrinos is about 0.5 degrees. In the range 1-100 TeV ANTARES has a
competitive sensitivity to this position in the sky.
GCN Circular 26554
Subject
LIGO/Virgo S191222n: not observable by Fermi-GBM
Date
2019-12-22T14:27:01Z (5 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), Fermi was passing through the South
Atlantic Anomaly from 17.8 minutes prior to 9.3 minutes after the trigger
time; therefore the GBM detectors were disabled.
GCN Circular 26556
Subject
LIGO/Virgo S191222n: No counterpart candidates in Fermi-LAT observations
Date
2019-12-22T15:26:14Z (5 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>*
--
Av��s -
Aviso - Legal Notice - (LOPD) - http://legal.ifae.es
<http://legal.ifae.es/>
GCN Circular 26557
Subject
LIGO/Virgo S191222n: no counterpart candidates in the Swift/BAT observations
Date
2019-12-22T16:57:53Z (5 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 26571
Subject
LIGO/Virgo S191222n: no counterpart candidate in SVOM/GWAC observations
Date
2019-12-24T02:40:16Z (5 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 26572
Subject
LIGO/Virgo S191222n: Updated Sky Localization
Date
2019-12-24T07:01:34Z (5 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 26575
Subject
LIGO/Virgo S191222n : No significant candidates in FRAM-TAROT-GRANDMA observations
Date
2019-12-24T14:25:27Z (5 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 26602
Subject
LIGO/Virgo S191222n: No transient candidates in CALET observations
Date
2019-12-28T06:20:43Z (5 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 26836
Subject
LIGO/Virgo S191222n: Upper limits from Konus-Wind observations
Date
2020-01-21T08:49:08Z (5 years ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
A. Ridnaia, S. Golenetskii, R.Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline,
on behalf of the Konus-Wind team, report:
Konus-Wind (KW) was observing the whole sky at the time of the
LIGO/Virgo event 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 26868
Subject
LIGO/Virgo S191222n: AstroSat CZTI upper limits
Date
2020-01-24T05:14:59Z (5 years ago)
From
Varun Bhalerao at Indian Inst of Tech <varunb@iitb.ac.in>
V. Shenoy (IITB), Aarthy E. (PRL), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao (TIFR), S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
We have carried a search for X-ray candidates in Astrosat CZTI data in a 100 sec window around the trigger time of the 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.