GCN Circular 30649
Subject
IceCube-210811A: Upper limits from Fermi-GBM Observations
Date
2021-08-16T21:06:34Z (3 years ago)
From
Cori Fletcher at USRA <cfletcher@usra.edu>
C. Fletcher (USRA) reports on behalf of the Fermi-GBM team:
For the IceCube high-energy neutrino candidate event IceCube-210811A
(GCN 30627), at the event time Fermi-GBM was observing the reported
neutrino location at:
RA: 270.79 (+1.07, -1.08 deg 90% PSF containment) J2000
Dec: 25.28 (+0.79, -0.84 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-210811A.
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: 8.7 11. 19.
1.024 s: 2.1 2.7 4.3
8.192 s: 1.1 1.4 1.5
These results are preliminary.