TITLE: GCN CIRCULAR NUMBER: 26345 SUBJECT: IceCube-191204A: Upper limits from Fermi-GBM Observations DATE: 19/12/05 16:51:29 GMT FROM: C. Michelle Hui at MSFC/Fermi-GBM C. M. Hui (MSFC) and P. Veres (UAH) report on behalf of the Fermi-GBM team: For the IceCube high-energy neutrino candidate event 191204A (GCN 26341), at the event time Fermi-GBM was observing the reported neutrino location at: RA: 79.72 (+3.20 -1.74 deg 90% PSF containment) J2000 Dec: 2.80 (+1.12 -1.23 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-191204A. 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: 15 20 37 1.024 s: 3.4 4.4 12 8.192 s: 1.3 2.3 3.6