TITLE: GCN CIRCULAR NUMBER: 35342 SUBJECT: GRB 231214A: Fermi-LAT detection DATE: 23/12/15 06:25:50 GMT FROM: Makoto Arimoto at Tokyo Inst of Tech <arimoto@hp.phys.titech.ac.jp> D. Kocevski (NASA/MSFC), N. Di Lalla (Stanford University), M. Arimoto (Kanazawa University), and T. Khalil (Johannesburg University) report on behalf of the Fermi-LAT Collaboration: On December 14, 2023 Fermi-LAT detected high-energy emission from GRB 231214A, which was also detected by Fermi-GBM (trigger 724278269.684604 / 231214850, GCN 35334), Swift-BAT and Swift-XRT (GCN 35335, 35341). The best LAT on-ground location is found to be RA, Dec = 306.1, -72.4 (degrees, J2000) with an error radius of 0.2 deg (90% containment, statistical error only). This was 51 deg from the LAT boresight at the time of the GBM trigger: T0 = 20:24:24.69 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 0-3000 s after the GBM trigger is (3.9 +/- 0.8)E-6 ph/cm2/s. The estimated photon index above 100 MeV is -1.9 +/- 0.2. The highest-energy photon is a 2.9 GeV event which is observed 414 seconds after the GBM trigger. The Fermi-LAT point of contact for this burst is Tamador Khalil (tamtam2030@gmail.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. View this GCN Circular online at https://gcn.nasa.gov/circulars/35342. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...