{
  "bibcode": "2009GCN..9895....1G",
  "body": "A. Goldstein (UAH) reports on behalf of the Fermi GBM Team: \n\n\"At 01:24:13.93 UT on 04 September 2009, the Fermi Gamma-Ray Burst Monitor\ntriggered and located GRB 090904B (trigger 273720255 / 090904058), \nwhich was also detected by the SWIFT-BAT (D'Elia et al. 2009, GCN 9881).\nThe GBM on-ground location is consistent with the Swift position.\nThe angle from the Fermi LAT boresight is 113 degrees.\n\nThe GBM light curve consists of three bright peaks\nwith a duration (T90) of about 71 s (8-1000 keV). \nThe time-averaged spectrum from T0-9.2 s to T0+65.5 s is \nwell fit by a power law function with an exponential\nhigh energy cutoff.  The power law index is 1.41 +/- 0.08 and\nthe cutoff energy, parameterized as Epeak, is 149.30 +/- 22.10 keV\n(chi squared 243.6 for 238 d.o.f.).\n\nThe event fluence (8-1000 keV) in this time interval is \n(2.44 +/- 0.15)E-05 erg/cm^2. The 1-sec peak photon flux measured \nstarting from T0+21.5 s in the 8-1000 keV band \nis 9.8 +/- 0.7 ph/s/cm^2.\n\nA Band function fits the spectrum equally well \n(chi squared 239.0 for 237 d.o.f.) with Epeak= 106.30 +/- 24.60 keV, \nalpha = -1.26 +/- 0.15 and beta = -2.18 +/- 0.18. \n\n\nThe spectral analysis results presented above are preliminary; \nfinal results will be published in the GBM GRB Catalog.\"",
  "circularId": 9895,
  "createdOn": 1252101707000,
  "email": "adam.m.goldstein@msfc.nasa.gov",
  "subject": "GRB 090904B: Fermi GBM detection",
  "submitter": "Adam Goldstein at Fermi-GBM/UAH  <adam.m.goldstein@msfc.nasa.gov>",
  "eventId": "GRB 090904B"
}