GCN Circular 37979
Subject
GRB 241030A: Fermi-LAT detection
Date
2024-10-30T18:34:51Z (a month ago)
From
Roberta Pillera at Politecnico and INFN Bari <roberta.pillera@ba.infn.it>
Via
Web form
GRB 241030A: Fermi-LAT detection
R. Pillera (INFN Bari), R. Gupta (NASA GSFC), D. Kocevski (NASA/MSFC), and P. Loizzo (UniTrento and INFN Bari) report on behalf of the Fermi-LAT Collaboration:
On Oct 30, 2024, Fermi-LAT detected high-energy emission from GRB 241030A, which was also detected by Fermi-GBM (trigger 751960088 / 241030242, GCN 37955), Swift-BAT (Klingler et al., GCN 37956), and SVOM-GRM (Wang et al., GCN 37972).
The best LAT on-ground location is found to be:
RA, Dec = 343.0, 80.4 (J2000)
with an error radius of 0.2 deg (90 % containment, statistical error only).
This was 16 deg from the LAT boresight at the time of the GBM trigger: T0 = 05:48:03 UT.
The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the GBM emission with high significance. The photon flux above 100 MeV in the time interval 0-800 s after the GBM trigger is (4.0 +/- 1.0) E-6 ph/cm2/s. The estimated photon index above 100 MeV is -2.13 +/- 0.27.
The highest-energy photon is a 2 GeV event which is observed ~ 470 seconds after the GBM trigger.
The Fermi-LAT point of contact for this burst is Roberta Pillera (roberta.pillera@ba.infn.it).
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.