GCN Circular 26622
Subject
IceCube-191231A: Upper limits from Fermi-GBM Observations
Event
Date
2019-12-31T23:05:00Z (6 years ago)
From
C. Michelle Hui at MSFC/Fermi-GBM <c.m.hui@nasa.gov>
C. M. Hui (MSFC) reports on behalf of the Fermi-GBM team:
For the IceCube high-energy neutrino candidate event 191231A (GCN 26620), at the event time Fermi-GBM was observing the reported neutrino location at:
RA: 46.36 (+4.27 -3.47 deg 90% PSF containment) J2000
Dec: 20.42 (+2.11 -2.80 deg 90% PSF containment) J2000
There was no Fermi-GBM onboard trigger around the event time of the neutrino candidate. 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 the neutrino candidate time. From this search, no significant signal was found related to IceCube-191231A.
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^-7 erg/s/cm^2):
Timescale�� Soft �� �� Normal �� Hard
-------------------------------------------
0.128 s:�� �� �� 6.5 �� �� 10.�� �� �� 19.��
1.024 s:�� �� �� 1.7�� �� �� 2.6�� �� �� 4.5��
8.192 s:�� �� �� 0.3�� �� �� 0.6�� �� �� 1.4��