GCN Circular 17216
Subject
GRB 141221A: Fermi GBM observation
Event
Date
2014-12-22T08:29:06Z (11 years ago)
From
Hoi-Fung Yu at MPE <sptfung@mpe.mpg.de>
H.-F. Yu (MPE) reports on behalf of the Fermi GBM Team:
"At 08:07:11.22 UT on 21 Dec 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 141221A (trigger 440842034 / 141221338),
which was also detected by Swift (Sonbas et al. 2014, GCN 17206).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is about 76 degrees.
The GBM light curve consists of two pulses with a duration (T90) of
about 23.8 s (50-300 keV). The time-averaged spectrum from T0-1.024 s
to T0+17.408 s is best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.07 +/- 0.13 and the
cutoff energy, parameterized as Epeak, is 152.4 +/- 28.5 keV.
The event fluence (8-1000 keV) in this time interval is
(3.4 +/- 0.4)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0-0.192 s in the 8-1000 keV band
is 5.4 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."