GCN Circular 28907
Subject
GRB 201116A: Fermi-LAT detection
Date
2020-11-16T14:09:02Z (4 years ago)
From
Frederic Piron at CNRS/IN2P3/LUPM <piron@in2p3.fr>
M. Axelsson (KTH & Stockholm Univ.), M. Ohno (Hiroshima Univ. & Eotvos
Univ.),
E. Bissaldi (Politecnico & INFN Bari), F. Longo (University and INFN,
Trieste) and
F. Piron (CNRS/IN2P3/LUPM) report on behalf of the Fermi-LAT Collaboration:
On November 16, 2020 Fermi-LAT detected high-energy emission from
GRB 201116A, which was also detected by Fermi-GBM (trigger 627180592,
GCN 28897).
The best LAT on-ground location is found to be
RA, Dec 149.33, 0.32 (degrees, J2000)
with an error radius of 0.24 deg (90% containment, statistical error only).
This was 14 deg from the LAT boresight at the time of the GBM trigger:
T0 = 00:49:47 UT.
The data from the Fermi-LAT show a significant increase
in the event rate after the GBM trigger that is spatially correlated
with the
GBM emission (4 degrees from the GBM location) with high significance.
The photon flux above 100 MeV in the time interval 0-1000s after the
GBM trigger is (2.25+/-0.07)e-06 ph/cm2/s.
The estimated photon index above 100 MeV is -1.9 +/- 0.3.
The highest-energy photon is a 2.4 GeV event which is observed 82
seconds after the GBM trigger.
A Swift ToO has been approved for this burst.
The Fermi-LAT point of contact for this burst is
Frederic Piron (piron@in2p3.fr).
The Fermi-LAT is a pair conversion telescope designed to cover
the energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration between
NASA and DOE in the U.S. and many scientific institutions
across France, Italy, Japan and Sweden.