GCN Circular 15659
Subject
GRB 140102A: Fermi-LAT detection of a burst
Date
2014-01-03T12:02:52Z (10 years ago)
From
Eda Sonbas at NASA/GSFC <edasonbas@gmail.com>
E. Sonbas (Adiyaman Univ.), G. Vianello (Stanford University) and F. Longo
(University and INFN, Trieste) report on behalf of the Fermi-LAT team:
The Fermi Large Area Telescope (LAT) detected emission from GRB 140102A,
also detected by Swift (Hagen et al., GCN 15653) and GBM (trigger
140102887) at 21:17:37.64 UT on January 02, 2014.
The GRB was detected at high enough peak flux in the GBM detectors to
trigger an autonomous repoint of the spacecraft. The source was 47 deg from
the LAT boresight at the time of the trigger, and then was kept close to
the boresight of the LAT up to 1200 seconds after the trigger. It entered
again the LAT field of view from T0+3400 to T0+7000 s.
Only the first couple of hundreds seconds of LAT data have been processed.
They show an excess temporally and spatially correlated with the emission
detected by Swift and by the GBM with very high significance. More than 20
photons above 100 MeV and more than 5 photons above 1 GeV are observed
within the first ~650 seconds. The highest energy photon is a 8 GeV event
which is observed 520 seconds after the GBM trigger.
The best LAT on-ground location is found to be RA, Dec 211.88, 1.36 (J2000)
with an error radius of 0.25 deg (90% containment, statistical error only),
which is 0.05 deg from the afterglow candidate detected and localized by
Swift/UVOT (GCN 15653).
The Fermi LAT point of contact for this burst is Eda Sonbas (
edasonbas@yahoo.com).
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.