{
  "bibcode": "2009GCN..9867....1D",
  "body": "Francesco de Palma (Universit� e INFN Bari), Johan Bregeon (INFN,  \nPisa) and Hiro Tajima (SLAC) report on behalf of the Fermi LAT team:\n\nAt 11:05:15 UT on 2 Sep 2009, the Fermi Large Area Telescope (LAT)  \ndetected gamma rays from the long GRB 090902B, which was triggered and  \nlocated by the Fermi Gamma-ray Burst Monitor (GBM) (trigger  \n273582310/090902462, GCN9866). The angle of the GBM best position (RA,  \nDec= 264.5, 26.5) with respect to the LAT boresight was 51 degrees at  \nthe time of the trigger, which is close the edge of our field of view.\n\nThe data from the Fermi LAT show a significant increase in the event  \nrate within 1 degree of the GBM location after the GBM trigger that is  \nspatially and temporally correlated with the GBM emission with high  \nsignificance. More than 200 photons above 100 MeV and more than 30  \nphotons above 1 GeV are observed within 100 seconds. The highest  \nenergy photon is a 33.4 GeV event which is observed 82 seconds after  \nthe GBM trigger.\n\nThe best LAT on-ground localization is found to be (RA,Dec=265.00,  \n27.33) with a 90% containment radius of 0.06 deg (statistical; 68%  \ncontainment radius: 0.04 deg, preliminary systematic error is less  \nthan 0.1 deg) which is consistent with the GBM localization. A Swift  \nTOO request has been issued.\n\nFurther analysis is ongoing.\n\nThe point of contact for this burst is\n\nFrancesco de Palma (francesco.depalma@ba.infn.it)\n\n\nThe Fermi LAT is a pair conversion telescope designed to cover the  \nenergy band from 20 MeV to greater than 300 GeV.\nIt is the product of an international collaboration between NASA and  \nDOE in the U.S. and many scientific institutions across France, Italy,  \nJapan and Sweden.\n\nThis message can be cited.",
  "circularId": 9867,
  "createdOn": 1251931698000,
  "email": "htajima@slac.stanford.edu",
  "subject": "GRB 090902B: Fermi LAT detection",
  "submitter": "Hiroyasu Tajima at SLAC  <htajima@slac.stanford.edu>",
  "eventId": "GRB 090902B"
}