[vsnet-grb-info 12396] GRB 120913A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13771
SUBJECT: GRB 120913A: Fermi GBM observation
DATE:    12/09/15 01:44:42 GMT
FROM:    Veronique Pelassa at UAH  <vero.pelassa at gmail.com>

V. Pelassa and V. Connaughton (UAH) report on behalf of the Fermi GBM Team:

"At 20:18:22.89 UT on 13 spetember 2012, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 120913A (trigger369260305  / 120913846), which was
also detected by the Swift/BAT (E.A. Helder et al. 2008, GCN 13762).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 97 degrees.

The GBM light curve consists of 2 peaks at T0 and T0+20s with a duration (T90)
of about 41s (50-300 keV).

The event fluence (10-1000keV) from T0-3.584 s to T0+33.280 s is
(1.8 +/- 0.3)E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting
from T0+21.568 s in the 10-1000 keV band is 3.8 +/- 0.2 ph/s/cm^2.

The first peak is harder but fainter than the second peak, which is
best fit by a
power law function with an exponential high-energy cutoff. The power law
index is -1.25 +/- 0.38 and the cutoff energy, parameterized as Epeak, is
26 +/- 4 keV (C-stat 372 for 366 d.o.f.).

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