[vsnet-grb-info 12946] GRB 130310A: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14283
SUBJECT: GRB 130310A: Fermi GBM detection
DATE:    13/03/11 08:48:12 GMT
FROM:    Shaolin Xiong at UAH  <sx0002 at uah.edu>

Shaolin Xiong (UAH) and Vandiver Chaplin (UAH)
report on behalf of the Fermi GBM Team:

"At 20:09:41.50 UT on 10 March 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 130310A (trigger 384638984 / 130310840),
which was also detected by the Fermi/LAT (Guiriec et al. 2013, GCN 14282)
The GBM on-ground location is consistent with the LAT position.
At the time of triggering the angle from the Fermi LAT boresight was
79 degrees. GBM generated a Autonomous Repointing
Request (ARR) due to the high peak flux of this GRB, causing
Fermi to reorient so that the LAT could better observe this GRB.

The GBM light curve consists of a precursor and a FRED pulse
with a duration (T90) of about 2.4 s (50-300 keV).
The time-averaged spectrum from T0+4.1 s to T0+5.0 s is
adequately fit by a Band function with Epeak = 2.1 +/- 0.2 MeV,
alpha = -1.01 +/- 0.02, and beta = -2.27 +/- 0.1.

The event fluence (10-1000 keV) in this time interval is
(1.4 +/- 0.02)E-5 erg/cm^2. The 0.064 sec peak photon flux measured
starting from T0+4.1 s in the 10-1000 keV band is 170 +/- 3 ph/s/cm^2.

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