Back
GCN Circular 21711

Subject
LIGO/VIRGO G299232: Fermi GBM Observations
Date
2017-08-26T03:11:21Z (8 years ago)
From
Rachel Hamburg at UAH <rkh0007@uah.edu>
LIGO/VIRGO G299232: Fermi GBM Observations

R. Hamburg (UAH) reports on behalf of the GBM-LIGO Group:
L. Blackburn (CfA), M. S. Briggs (UAH), J. Broida (Carleton College), E.
Burns (NASA/GSFC), J. Camp (NASA/GSFC), T. Dal Canton (NASA/GSFC), N.
Christensen (Carleton College), V. Connaughton (USRA), A. Goldstein (USRA),
C.M. Hui (NASA/MSFC), P. Jenke (UAH), D. Kocevski (NASA/MSFC), N. Leroy
(LAL), T. Littenberg (NASA/MSFC), J. McEnery (NASA/GSFC), R. Preece (UAH),
J. Racusin (NASA/GSFC), P. Shawhan (UMD), K. Siellez (GATech), L. Singer
(NASA/GSFC), J. Veitch (Birmingham), P. Veres (UAH), C. Wilson-Hodge
(NASA/MSFC)

At the G299232 event time (2017-08-25 13:13:37 UTC), Fermi GBM was taking
data and viewing the entire un-occulted sky approximately 67 degrees from
Earth center (RA = 54.6,Dec = 7.8), which includes 36% of the LIGO BAYESTAR
HLV map.

No on-board triggers occurred within an hour of the GW trigger time.
The untargeted ground-based search of GBM data for short-duration GRBs
(Briggs et al., in prep) also did not find any significant candidate within
one hour of the GW trigger.

The targeted search of the GBM data ([1],[2]) searched +/- 30 s around the
GW event time, processing time scales of 0.256 to 8.192 s. One event with a
soft spectrum was found on a 4 s timescale approximately 27 s after the GW
time. The initial estimated False Alarm Rate (FAR) is 4.6e-4 Hz (90%
confidence). The localization returned by the search does not overlap with
the LHV Bayestar localization region. We conclude that this signal is
unassociated with the GW event.

The targeted search was also run +/- 30 s around the gamma-ray candidate
reported by AGILE MCAL (Carrillo et al., 2017, GCN 21700Loading...
 
 ). No significant
candidates were found.

[1] L. Blackburn et al. 2015, ApJS 217, 8
[2] A. Goldstein et al. arXiv:1612.02395Loading...