TITLE: GCN CIRCULAR NUMBER: 25026 SUBJECT: LIGO/Virgo S190707q: Upper limits from Fermi-GBM Observations DATE: 19/07/07 21:42:02 GMT FROM: Adam Goldstein at Fermi-GBM, USRA A. Goldstein (USRA) reports on behalf of the Fermi-GBM Team and the GBM-LIGO/Virgo group: For the LIGO/Virgo detection of GW trigger S190707q (GCN 25012) and using the initial BAYESTAR skymap, Fermi-GBM was observing 46.3% of the localization probability at event time. There was no Fermi-GBM onboard trigger around the event time of S190707q. 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 merger time, and also identified no counterpart candidates. Part of the LVC localization region is behind the Earth for Fermi, located at RA = 171.8 and Dec = -21.4 with a radius of 67.4 degrees. We therefore 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, weighted by the GW localization probability, (in units of 10^-7 erg/s/cm^2): Timescale soft norm hard -------------------------------------- 0.128 s: 2.5 4.0 8.9 1.024 s: 0.8 1.2 2.2 8.192 s: 0.4 0.4 0.8 Assuming the median luminosity distance of 809.8 Mpc (z=0.167) from the GW detection, we estimate the following intrinsic luminosity upper limits over the 1 keV-10 MeV energy range (in units of 10^49 erg/s): Timescale soft norm hard -------------------------------------- 0.128 s: 3.0 4.4 16. 1.024 s: 1.0 1.3 4.0 8.192 s: 0.5 0.5 1.5