TITLE: GCN CIRCULAR NUMBER: 22043 SUBJECT: Fermi GBM Observations of IceCube-171015A DATE: 17/10/23 01:11:41 GMT FROM: Rachel Hamburg at UAH R. Hamburg (UAH) and A. Goldstein (USRA) report on behalf of the Fermi GBM team: We have searched the Fermi Gamma-ray Burst Monitor data for a gamma-ray counterpart to the IceCube neutrino 171015A (GCN 22016). The location of the neutrino was observed by GBM with good geometry. There were no associated on-board triggers +/- 15 hours of the neutrino event time. The ground-based untargeted search of GBM data (Briggs et al., in prep) did not find any candidates +/- 1 hour of the event time. The targeted search of GBM data ([1],[2]) also searched +/- 30 s around the neutrino event time, processing timescales of 0.256 s to 8.192 s. No significant candidates were found. Using a hard Band function with (Epeak, alpha, beta) = (500 keV, -0.5,-2.5), we set 3 sigma flux-averaged upper limits for any transient within 30 s of the neutrino event time. Averaged over (0.1 s, 1 s, and 10 s) timescales, the corresponding upper limits in the 10-1000 keV band are (16.4, 4.82, 1.47) E-7 erg/s/cm^2. Using an exponentially cut-off power law parametrized with (Epeak, index) = (566 keV, -0.42), which represents the average GBM-triggered short GRB, the flux-averaged upper limits are (18.0, 5.26, 1.61) E-7 erg/s/cm^2. [1] L. Blackburn et al. 2015, ApJS 217, 8 [2] A. Goldstein et al. arXiv:1612.02395