GCN Circular 15975
Subject
GRB 140311B: Fermi GBM Detection
Date
2014-03-12T20:40:40Z (10 years ago)
From
Matthew Stanbro at UAH/Fermi <mcs0001@uah.edu>
M. Stanbro (UAH) reports on behalf of the Fermi GBM Team:
"At 21:14:35.65 UT on 11 March 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 140311B (trigger 416265278/140311885),
which was also detected by Swift (J. L. Racusin et al. 2014, GCN 15945).
The GBM on-ground location, using the Fermi GBM trigger
data, is consistent with the Swift/BAT location.The angle to the
Fermi LAT boresight is 110 deg. from Swift location.
The GBM light curve consists of several overlapping peaks with a
combined duration (T90) of 72 s (50-300 keV).
The time-averaged spectrum from T0-3 s to T0+69 s is
well fit by a power law function with an exponential
high energy cutoff. The power law index is -0.5 +/- 0.1
and the high energy cutoff, parameterized as
Epeak, is 117 +/- 8 keV.
The event fluence (10-1000 keV) in this time interval is
(7.9 +/- 0.4)E-06 erg/cm^2. The 1.0-sec peak photon flux measured
starting from T0+0.6 s in the 10-1000 keV band
is 3.2 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."