TITLE: GCN CIRCULAR NUMBER: 25807 SUBJECT: IceCube-190922A: Upper limits from Fermi-GBM Observations DATE: 19/09/23 05:27:26 GMT FROM: Eric Burns at GSFC E. Burns (NASA/GSFC) reports on behalf of the Fermi-GBM Team: For the IceCube high-energy neutrino candidate event 190922A (GCN 25802), at the event time Fermi-GBM was observing about half the reported neutrino probability map of: RA: 167.43 (+ 3.40 - 2.63 deg 90% PSF containment) J2000 Dec: -22.39 (+ 2.88 - 2.89 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-190922A. Over the 1 minute search interval the Earth-occulted region for Fermi shifted by about 4 degrees, resulting in time-varying exposure to the neutrino localization. We set upper limits on impulsive gamma-ray emission for the fraction of localization region observed as a function of time. Using the representative soft, normal, and hard GRB-like templates (arXiv:1612.02395), we report the following 3 sigma flux upper limits over 10-1000 keV (in units of 10^-7 erg/s/cm^2): Timescale soft norm hard -------------------------------------- 0.128 s: 3.8 6.3 13. 1.024 s: 1.0 1.8 3.7 8.192 s: 0.3 3.9 1.0