GCN Circular 13754
Subject
GRB 120911A: Fermi GBM observation
Date
2012-09-12T07:02:43Z (12 years ago)
From
David Gruber at MPE <dgruber@mpe.mpg.de>
David Gruber (MPE) reports on behalf of the Fermi GBM Team:
"At 07:08:33.99 UT on 11 September 2012, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 120911A (trigger 369040116 / 120911298).
which was also detected by the Swift/BAT (Cannizzo et al. 2012, GCN 13744).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 11 degrees.
The GBM light curve consists of two pulses
with a duration (T90) of about 22 s (50-300 keV).
The time-averaged spectrum from T0-4.6 s to T0+22.0 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.36 +/- 0.26 and
the cutoff energy, parameterized as Epeak, is 64.2 +/- 5.1 keV
The event fluence (10-1000 keV) in this time interval is
(2.34 +/- 0.04)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.38 s in the 10-1000 keV band
is 4.31 +/- 0.27 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."