GCN Circular 12386
Subject
GRB 110921A: Fermi GBM observation
Date
2011-09-22T15:47:15Z (13 years ago)
From
Gerard Fitzpatrick at UCD <gerard.fitzpatrick@ucdconnect.ie>
G. Fitzpatrick (UCD) reports on behalf of the Fermi GBM Team:
"At 13:51:22.57 UT on 21 September 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110921A (trigger 338305884 / 110921577),
which was detected by the Swift/BAT (Baumgartner et al. 2011, GCN 12373).
The GBM on-ground location is consistent with the Swift position.
The GBM light curve shows a single bright
peak with a duration (T90) of ~37 s (50-300 keV).
The time-averaged spectrum from T0-26 s to T0+9 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.39 +/- 0.12 and
the cutoff energy, parameterized as Epeak, is 139 +/- 32 keV.
The event fluence (10-1000 keV) in this time interval is
(4.2 +/- 0.4)E-06 erg/cm^2. The 1 s peak photon flux measured
starting from T0+0.5 s in the 10-1000 keV band
is 2.9 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."