Gamma-ray Follow-up of the LIGO/Virgo Third Observational Run (O3) with Fermi-GBM

The Fermi Gamma-ray Burst Monitor (GBM) is a nearly full-sky gamma-ray instrument that has been pivotal in advancing multimessenger astronomy by providing simultaneous observations of gamma-ray bursts (GRBs) with gravitational-wave (GW) candidates from the Advanced LIGO and Advanced Virgo instruments. During the second LIGO/Virgo observing run the link between short GRBs and GWs was confirmed with the detection of GRB 170817A in coincidence with the binary neutron star merger GW170817. A large multiwavelength follow-up campaign was set in motion following this groundbreaking detection. Since most mergers are observed at farther distances than GW170817, the Fermi-GBM team has developed an algorithm, called the Targeted Search, to examine the continuous data for GRBs coincident to GW candidates below the onboard triggering threshold. O3 ran for almost a year and produced many GW candidates that were publicly announced. We present a follow-up of O3 using the Fermi-GBM Targeted Search that has been updated to increase sensitivity in identifying GRB counterparts to gravitational-wave candidates