GCN Circular 37855
Subject
EP241021a: No Detection in Fermi-GBM Observation
Date
2024-10-24T16:04:58Z (a month ago)
From
Eric Burns at LSU <erickayserburns@gmail.com>
Via
Web form
E. Burns (LSU), M. E. Ravasio and P.G. Jonker (Radboud Univ.), and Adam Goldstein (USRA) report on behalf of the Fermi-GBM Team:
Fermi-GBM had full spatial and temporal coverage of the EP WXT signal of EP241021a (Hu et al., GCN 37834).
There was no Fermi-GBM onboard trigger around the event time of EP241021a. 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 before the EP trigger time until 300 s after, seeking signals between 64 ms and 32.768 s in duration. A candidate was found, but it has a localization that is not consistent with the EP trigger and appears to be a soft Galactic source that becomes occulted by the Earth at approximately T0+40 s. No signal consistent both temporally and spatially is identified, as confirmed by visual inspection of the data.