GRB 210306A: Fermi-LAT detection
Abstract
On March 06, 2021, Fermi-LAT detected high-energy emission from GRB 210306A, which was also detected by Fermi-GBM (trigger 636695642), Swift (D'Elia et al.; GCN 29597), and confirmed the afterglow by ground telescopes (M. Watson et al.; GCN 29598, Dmitrievich Romanov; GCN 29599, Strausbaugh and. Cucchiara; GCN 29600). The best LAT on-ground location is found to be RA, Dec 130.3, 60.2 (degrees, J2000) with an error radius of 0.38 deg (90% containment, statistical error only). This was 10 deg from the LAT boresight at the time of the GBM trigger: T0 = 03:53:57.11 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 (5.8 degrees from the GBM location) with high significance. The photon flux above 100 MeV in the time interval 0-3000 s after the GBM trigger is (6.6+/-3.5 e-7) ph/cm2/s. The estimated photon index above 100 MeV is -2.0(+/-0.4). The highest-energy photon is a 1.9 GeV event which is observed 790 seconds after the GBM trigger. The Fermi-LAT point of contact for this burst is Milena Crnogorcevic (mcrnogor@astro.umd.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.
- Publication:
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GRB Coordinates Network
- Pub Date:
- March 2021
- Bibcode:
- 2021GCN.29602....1O