GCN Circular 26676
Subject
Fermi-LAT ANTARES coincidence: Upper limits from Fermi-GBM Observations
Date
2020-01-08T22:56:03Z (4 years ago)
From
Joshua Wood at MSFC/Fermi-GBM <joshua.r.wood@nasa.gov>
J. Wood (NASA/MSFC) reports on behalf of the Fermi-GBM Team:
For the Fermi-LAT ANTARES coincidence event on 2020 January 8th (GCN 26674), at the event time Fermi-GBM was observing the reported location at:
RA:�� 02:53:55.6 (J2000)
Dec: -18:04:02 (J2000)
r_90:�� 0.832 deg (90%-containment)
There was no Fermi-GBM onboard trigger around the event time of the concidence event. 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 before the identified neutrino event at 09:25:12 UT until 30 seconds after the detection of the Fermi LAT photon at 09:35:16.96 UT. From this search, no significant signal was found related to the reported location.
We 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 (in units of 10^-6 erg/s/cm^2):
Timescale�� Soft �� �� Normal �� Hard
--------------------------------------
0.128 s: �� 6.7�� �� �� 12.�� �� �� 21.
1.024 s: �� 1.7�� �� �� 2.5�� �� �� 5.0
8.192 s: �� 0.7�� �� �� 1.1�� �� �� 1.7