{
  "subject": "GRB 230903A: Fermi GBM detection",
  "submittedHow": "web",
  "bibcode": "2023GCN.34618....1R",
  "body": "O.J. Roberts (USRA), B. Mailyan (Florida Tech) and C. Meegan (UAH)\nreport on behalf of the Fermi GBM Team:\n\n\"At 17:22:58.81 UT on the 3rd September 2023 , the Fermi Gamma-Ray Burst Monitor (GBM)\ntriggered and located GRB 230903A (trigger 715454583 / 230903724) which was also detected \nby the Swift/BAT (A. D'ai et al. 2023, GCN 34610). The Fermi GBM Final Real-time Localization \n(GCN 34608) is consistent with the Swift position.\n\nThe angle from the Fermi LAT boresight at the GBM trigger time is 98 degrees.\n\nThe GBM light curve consists of one pulse\nwith a duration (T90) of about 3 s (50-300 keV).\nThe time-averaged spectrum from T0-4.0 s to T0+1.0 s is\nbest fit by a simple power law function with index -1.78 +/- 0.09.\n\nA power law function with an exponential high-energy cutoff fits\nthe spectrum equally well. The power law index is -1.27 +/- 0.33 \nand the cutoff energy, parameterized as Epeak, is 95 +/- 31 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(5.87 +/- 0.85)E-07 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0-1s in the 10-1000 keV band\nis 2.0 +/- 0.2 ph/s/cm^2.\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog:\nhttps://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html\n\nFor Fermi GBM data and info, please visit the official Fermi GBM Support Page:\nhttps://fermi.gsfc.nasa.gov/ssc/data/access/gbm/\"",
  "createdOn": 1693845658478,
  "circularId": 34618,
  "submitter": "Oliver J Roberts at USRA/NASA <oliver.roberts@nasa.gov>",
  "eventId": "GRB 230903A"
}