GCN Circular 17241
Subject
GRB 141225A: Fermi GBM detection
Date
2014-12-26T17:48:26Z (9 years ago)
From
Peter Jenke at MSFC <peter.a.jenke@nasa.gov>
P. Jenke (UAH) reports on behalf of the Fermi GBM Team:
"At 23:01:13.82 UT on December 25 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 141225A (trigger 441241276/141225959),
which was also detected by
Swift (P. D'Avanzo et al. 2014, GCN 17229). Additionally,
there were optical detections from the 1.23m CAHA telescope
(J. Gorosabel et al. 2014 GCN 17230) among others as well
as a redshift measurement (J. Gorosabel et al. 2014 GCN 17234).
The GBM on-ground location, using the Fermi GBM trigger
data, is consistent with the Swift/XRT and optical locations.
The angle of the burst direction to the Fermi LAT boresight
is 104 degrees.
The GBM light curve consists of one FRED-like peak with a
duration (T90) of about 56 s (50-300 keV).
The time-averaged spectrum from T0-4.1s to T0+21.5s
is well fit by a Band function with Epeak = 187 +/- 29 keV,
Alpha = -0.35 +/- 0.17 and Beta = -2.0 +/- 0.1.
The event fluence (10-1000 keV) in this time interval is
(6.5 +/- 0.3)E-06 ergs/cm^2. The 1.0-sec peak photon flux measured
starting from T0+9.7s in the 10-1000 keV band
is 2.5 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."