GCN Circular 17408
Subject
GRB 150204A: Fermi GBM detection
Date
2015-02-04T21:17:10Z (9 years ago)
From
Eric Burns at U of Alabama <eb0016@uah.edu>
E. Burns (UAH) and H.-F. Yu (MPE)
report on behalf of the Fermi GBM Team:
"At 06:31:07.88 UT on 04 February 2015, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 150204A (trigger 444724270 / 150204272) which
was also found in ground analysis of Swift/BAT data
(Cummings et al. 2015, GCN 17404). The GBM on-ground location is
consistent with the Swift position. The angle from the Fermi LAT boresight
is 54 degrees.
The GBM light curve consists of one main peak
with a duration (T90) of about 10 s (50-300 keV).
The time-averaged spectrum from T0-6.144 s to T0+7.168 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.4 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 350 +/- 143 keV
The event fluence (10-1000 keV) in this time interval is
(2.2 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.064 s in the 10-1000 keV band
is 3.1 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."