GCN Circular 38238
Subject
EP241113a: No Detection in Fermi-GBM Observations
Date
2024-11-15T15:28:34Z (19 days ago)
From
P.G. Jonker at Radboud University <p.jonker@astro.ru.nl>
Via
Web form
E. Burns (LSU), M. E. Ravasio (Radboud Univ.) and P.G. Jonker (Radboud Univ.) report on behalf of the Fermi-GBM Team:
Fermi-GBM had full spatial and temporal coverage of the EP WXT signal of EP241113a (Liu et al., GCN 38211).
There was no Fermi-GBM onboard trigger around the EP-WXT trigger time T0=2024-11-13T19:12:53 UTC, nor at the earlier starting time of the transient (as reported in the EP-WXT GCN 38211, 2024-11-13T19:09:19 UTC). An automated, blind search for a short gamma-ray burst 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 50 s before the EP trigger time until 500 s after both reported times, seeking signals between 64 ms and 32.768 s in duration. A candidate was found, but its localization is not consistent with the EP transient and appears to be a soft Galactic source. No signal consistent both temporally and spatially is identified, as confirmed by visual inspection of the data.