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GCN Circular 27758

Fermi GBM Sub-Threshold Detection of GRB 200517A
2020-05-19T16:46:54Z (4 years ago)
Cori Fletcher at USRA <>
C. Fletcher (USRA) reports on behalf of the Fermi-GBM Team:

MAXI/GSC detected GRB 200517A at 11:27:21 UT (GCN 27750). There was no
Fermi-GBM onboard trigger around the event.

An automated, blind search for short gamma-ray bursts below the onboard
triggering threshold in Fermi-GBM identified no counterparts.

The GBM targeted search [1], the most sensitive, coherent search for
GRB-like signals identified a transient most significantly on the 8.192 s
timescale, with a log likelihood ratio of 13 and a location consistent with
the MAXI/GSC event. The GBM targeted search event was found with the highest
significance with a "soft" spectrum (Band function with Epeak=70 keV, alpha=-1.9,
beta=-3.7) for a GRB.

[1] Goldstein et al. 2019 arXiv:1903.12597
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