GCN Circular 23709
Subject
GRB 190114C: Fermi-LAT detection
Date
2019-01-15T07:23:42Z (6 years ago)
From
Magnus Axelsson at Stockholm U. <magaxe@kth.se>
D. Kocevski, N. Omodei (Stanford U.), M. Axelsson (KTH & Stockholm Univ.), E. Burns (NASA/GSFC), G. Vianello (Stanford U.), E. Bissaldi (Politecnico & INFN Bari) and F. Longo (University and INFN Trieste) report on behalf of the Fermi-LAT team:
On January, 14, 2019, Fermi-LAT detected high-energy emission from GRB 190114C, which was also detected by the Fermi GBM (Hamburg et al. 2019, GCN 23707), Swift/BAT (Gropp et al. 2019, GCN 23688), and at Very High Energy by the MAGIC telescope (Mirzoyan et al. 2019, GCN 23701).
The best LAT on-ground location is found to be
RA, Dec = 54.57, -26.99 (degrees, J2000)
with an error radius of 0.05 deg (90% containment, statistical error only). This position is consistent with the Swift/BAT localization. The LAT position was 68 deg from the LAT boresight at the time of the GBM trigger time (20:57:02.63 UT) and remained in the LAT field of view for 150 seconds.
The data from the Fermi-LAT show a significant increase in the event rate that is spatially correlated with the GBM trigger with high significance. The highest-energy photon is a 22.9 GeV event which is observed 15 s after the GBM trigger.
The estimated photon index above 100 MeV is -1.98 +/- 0.06, with an estimated photon and energy flux of 2.69e-03 +/- 1.86e-04 ph/cm2/s and 2.06e-06 +/- 1.42e-07 erg/cm2/s, respectively.
The Fermi-LAT point of contact for this burst is Daniel Kocevski (kocevski@slac.stanford.edu<http://slac.stanford.edu>).
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.