GCN Circular 26409
Subject
LIGO/Virgo S191213g: Upper limits from Fermi-GBM Observations
Date
2019-12-13T13:56:20Z (5 years ago)
From
Colleen A. Wilson at NASA/MSFC/NSSTC <colleen.wilson@nasa.gov>
C.A. Wilson-Hodge (NASA/MSFC) reports on behalf of the Fermi-GBM Team and the GBM-LIGO/Virgo group
For S191213g and using the initial bayestar.fits.gz skymap, Fermi-GBM was observing 99.9% of the localization probability at event time.
There was no Fermi-GBM onboard trigger around the event time of the LIGO/Virgo detection of GW trigger S191213g (GCN 26402). An automated, blind search for short gamma-ray bursts below the onboard triggering threshold in Fermi-GBM also identified no counterpart candidates. The GBM targeted search, the most sensitive, coherent search for GRB-like signals, was run from +/-30 s around merger time, and also identified no counterpart candidates.
We therefore set upper limits on impulsive gamma-ray emission. Using the representative soft, normal, and hard GRB-like templates described in arXiv:1612.02395, we set the following 3 sigma flux upper limits over 10-1000 keV, weighted by GW localization probability (in units of 10^-7 erg/s/cm^2):
Timescale soft norm hard
--------------------------------------
0.128 s: 5.4 8.9 14.
1.024 s: 2.1 2.8 6.3
8.192 s: 0.63 0.96 1.6
Assuming the median luminosity distance of 194.9 Mpc from the GW detection, we estimate the following intrinsic luminosity upper limits over the 1 keV-10 MeV energy range (in units of 10^48 erg/s):
Timescale Soft Normal Hard
------------------------------------
0.128 s: 3.7 5.7 15.
1.024 s: 1.5 1.8 6.7
8.192 s: 0.44 0.62 1.7