GCN Circular 28530
Subject
IceCube-200926A: Upper limits from Fermi-GBM Observations
Date
2020-09-29T19:51:21Z (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 IceCube high-energy neutrino candidate event IceCube-200926A
(GCN 28504), at the event time Fermi-GBM was observing the reported
neutrino location at:
RA: 96.46 (+ 0.73 - 0.55 deg 90% PSF containment) J2000
Dec: -4.33 (+ 0.61 - 0.76 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-200926A.
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: 7.1 9.7 17.
1.024 s: 2.3 3.4 5.9
8.192 s: 1.0 1.5 2.6
These results are preliminary.