GCN Circular 13809
Subject
GRB 120922A: Fermi GBM detection
Date
2012-09-23T18:23:16Z (12 years ago)
From
George A. Younes at USRA/NASA/MSFC <younes.ge@gmail.com>
George Younes (MSFC/USRA) reports on behalf of the Fermi GBM Team:
"At 22:32:09.47 UT on 22 September 2012, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 120922A (trigger 370045932 / 120922939)
which was also detected by the Swift/BAT (Yershov et al. 2012, GCN 13793).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 85 degrees.
The GBM light curve consists of a multiple peaks with a duration (T90)
of about 180 s (50-300 keV).
The time-averaged spectrum from T0-121 s to T0+6 s is
best fit by a Band function with Epeak = 37.7 +/- 3.5 keV,
alpha = 1.6 +/- 0.7 , and beta = -2.3 +/- 0.1.
The event fluence (10-1000 keV) in this time interval is
(6.5 +/- 0.4)E-06 ergs/cm^2. The 1-sec peak photon flux measured
starting from T0-1.8 s in the 10-1000 keV band
is 3.4 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."