GCN Circular 26330
Subject
GRB 191202A: Fermi-LAT detection
Date
2019-12-03T20:04:05Z (5 years ago)
From
Lorenzo Scotton at CNRS/IN2P3/LUPM <lorenzoscotton@live.it>
D. Kocevski (NASA/GSFC), R. Angioni (ASI/SSDC and INFN, Roma2), F. Longo (University and INFN, Trieste),
N. Omodei (Stanford University), E. Bissaldi (Politecnico and INFN, Bari) and L. Scotton (CNRS/IN2P3/LUPM, Montpellier)
report on behalf of the Fermi-LAT Collaboration:
On December 2nd, 2019, Fermi-LAT detected high-energy emission from
GRB 191202A, which was also detected by Fermi-GBM (trigger 597012536/191202867) (Veres et al. 2019, GCN 26329).
The best LAT on-ground location is found to be
RA, Dec = 249.54, 17.56 (degrees, J2000)
with an error radius of 0.24 deg (90% containment, statistical error only).
This was 11.4 deg from the LAT boresight at the time of the GBM trigger:
T0 = 20:48:51.23 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 with high significance.
The photon flux above 100 MeV in the time interval 0-1000s after the
GBM trigger is 2.6e-06 +/- 8.8e-07 ph/cm2/s.
The estimated photon index above 100 MeV is -1.6 +/- 0.2.
The highest-energy photon is a 1.8 GeV event which is observed 393 seconds
after the GBM trigger.
The Fermi-LAT point of contact for this burst is
Lorenzo Scotton (lorenzo.scotton@lupm.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.