GRB 190727B: Fermi-LAT detection
Abstract
On July 27, 2019, Fermi-LAT detected high-energy emission from GRB 190727B, which was also detected by Fermi-GBM (Veres et al., GCN 25180) and Swift-BAT (Lien et al., GCN 25176). The best LAT on-ground location is found to be RA, Dec 126.19, -13.34 (degrees, J2000) with an error radius of 0.28 deg (90% containment, statistical error only). This was 46 deg from the LAT boresight at the time of the GBM trigger: T0 = 20:17:56.45 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 0-1500 s after the GBM trigger is (3.15 +/- 1.25)E-6 ph/cm2/s. The highest-energy photon in this interval is a 2.2 GeV event observed at T0 + 345 s. The estimated photon index above 100 MeV is -2.3 +/- 0.4. The Fermi-LAT point of contact for this burst is Milos Kovacevic (milos.kovacevic@pg.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.
- Publication:
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GRB Coordinates Network
- Pub Date:
- July 2019
- Bibcode:
- 2019GCN.25186....1K