{
  "bibcode": "2022GCN.32862....1A",
  "body": "Arimoto M. (Kanazawa University), Bissaldi E. (Politecnico and INFN Bari),\nLongo F. (University and INFN Trieste), Scotton L. (CNRS/IN2P3/LUPM)\nand Maheso D. (Johannesburg Univ.) report on behalf of the Fermi-LAT\nteam:\n\nOn October, 27, 2022 Fermi-LAT detected high-energy emission from GRB 221027A,\nwhich was also detected by Fermi-GBM (trigger 221027173 / 688536579,\nGCN 32861) at 04:09:34.35 UT .\n\nThe best LAT on-ground location is found to be\n\nRA, Dec =  185.3, -5.7 (J2000)\n\nwith an error radius of 0.4 deg (90 % containment, statistical error only).\nThis was 51 deg from the LAT boresight at the time of the trigger.\n\nThe data from the Fermi-LAT show a significant increase in the event\nrate that is spatially\nand temporally correlated with the trigger with high significance.\n\n\nThe 100 MeV - 1 GeV photon flux in the time interval 0-500 s after\nthe GBM trigger is (9.1 +/- 2.6)E-06 ph/cm2/s.\nThe estimated integrated photon index above 100 MeV is -2.2 +/- 0.3.\nThe highest-energy photon is a 1.1 GeV event with 96% probability\nwhich is observed 26 seconds after the GBM trigger.\n\nA Swift ToO has been requested for this burst.\n\n\nThe Fermi-LAT point of contact for this burst is\nDimakatso Jeannett Maheso (d.j.maheso@gmail.com).\n\nThe Fermi-LAT is a pair conversion telescope designed to\ncover the energy band from 20 MeV to greater than 300 GeV.\nIt is the product of an international collaboration\nbetween NASA and DOE in the U.S. and many scientific\ninstitutions across France, Italy, Japan and Sweden.",
  "circularId": 32862,
  "createdOn": 1666866531000,
  "email": "arimoto@hp.phys.titech.ac.jp",
  "subject": "GRB 221027A: Fermi-LAT detection",
  "submitter": "Makoto Arimoto at Tokyo Inst of Tech  <arimoto@hp.phys.titech.ac.jp>",
  "eventId": "GRB 221027A"
}