GCN Circular 28735
Subject
IceCube-201021A: Upper limits from Fermi-GBM Observations
Date
2020-10-21T22:07:13Z (4 years ago)
From
Stephen Lesage at Fermi-GBM Team <sjl0014@uah.edu>
S. Lesage (UAH) reports on behalf of the Fermi-GBM team:
For the IceCube high-energy neutrino candidate event IceCube-201021A
(GCN 28715), at the event time Fermi-GBM was observing the reported
neutrino location at:
RA: 260.82 (+1.73 -1.68 deg 90% PSF containment) J2000
Dec: 14.55 (+1.35 -0.74 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-201021A.
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: 5.2 8.1 16.0
1.024 s: 2.5 3.5 5.9
8.192 s: 0.6 0.8 1.7
These results are preliminary.