[vsnet-grb-info 13105] GRB 130425A: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14442
SUBJECT: GRB 130425A: Fermi GBM detection
DATE:    13/04/25 15:24:49 GMT
FROM:    Andreas von Kienlin at MPE  <azk at mpe.mpg.de>

A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team:

"At 07:51:16.23 UT on 25 April 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 130425A (trigger 388569079 / 130425327).

The on-ground calculated location, using the GBM trigger data, 
is RA = 19.0, DEC = -72.2 (J2000 degrees, equivalent 
to 01 h 16 m, -72 d 12 '), with an uncertainty of 2.9 degrees 
(radius, 1-sigma containment, statistical only; there is additionally 
a systematic error which is currently estimated to be 2 to 3 degrees).

The angle from the Fermi LAT boresight is 150 degrees.

The GBM light curve shows two peaks  with a duration (T90) 
of about 66 s (50-300 keV). The time-averaged spectrum from 
T0-2.880 s to T0+69.825 s is best fit by a power law function 
with an exponential high-energy cutoff.  The power law index
 is -1.28 +/- 0.03  and the cutoff energy, parameterized as Epeak, is 254
(+14/-13) keV.

The event fluence (10-1000 keV) in this time interval is
(5.2 +/- 0.1)E-05 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+43.5207 s in the 10-1000 keV band
is 21.8 +/- 1.1 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."