TITLE: GCN CIRCULAR NUMBER: 44029 SUBJECT: EP260316a / GRB 260316A : Fermi-GBM Sub-Threshold Detection DATE: 26/03/16 17:06:07 GMT FROM: mariaedvige.ravasio@ru.nl M. E. Ravasio (ICE-CSIC and Radboud Univ.), P.G. Jonker (Radboud Univ.) and E. Burns (LSU), R. Hamburg (USRA), and P. Veres (UAH) report on behalf of the Fermi-GBM Team: Fermi-GBM had full spatial and temporal coverage of the transient EP260316a detected by EP-WXT (EP Team GCN 44027). There was no Fermi-GBM onboard trigger around the corrected EP starting time at T0 = 2026-03-16T12:33:13 UTC. The GBM Targeted Search [1], the most sensitive, coherent search for GRB-like signals, was run in the time interval [-50;+500] s from T0, seeking signals between 64 ms and 32.768 s in duration. A faint transient signal was found most significantly at ~T0-3.6 s on a 4 s timescale, with a false alarm rate of 6.5e-05 Hz, although there is evidence of an earlier start of the emission at T0-20 s. The localisation is consistent with the EP one, with a spatial association probability of 98.8%. Among the three spectral templates tested, the transient was best-fit with a“soft” spectral template (Band function with Epeak = 70 keV, alpha = -1.9, beta = -3.7) for a GRB. [1] Goldstein et al. 2019 arXiv:1903.12597 View this GCN Circular online at https://gcn.nasa.gov/circulars/44029. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...