[vsnet-grb-info 14141] GRB 131105A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15455
SUBJECT: GRB 131105A: Fermi GBM observation
DATE:    13/11/05 16:18:25 GMT
FROM:    Gerard Fitzpatrick at UCD  <gerard.fitzpatrick at ucdconnect.ie>

G. Fitzpatrick (UCD) and P. Jenke (UAH) report on behalf of the Fermi GBM
Team:

At 02:04:53.49 UT on 05 November 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 131105A (trigger 405309896/131105087), which
was also detected by Swift (Cummings et al., GCN 15446) and Konus-Wind
(Golenetskii et al, GCN 15452).  The GBM on-ground location is consistent
with the Swift/XRT position (Osborne et al., GCN 15448). The angle from
the Fermi LAT boresight is 37 degrees.

The GBM light curve consists of a multiple-peak structure with a duration
(T90) of about 112 s (50-300 keV). The time-averaged spectrum from
T0-3 s to T0+121 s is adequately fit by a Band function with Epeak =
203.9 +/- 31.1 keV, alpha = -1.2 +/- 0.1, and beta = -1.8 +/- 0.1.

The event fluence (10-1000 keV) in this time interval is
(2.9 +/- 0.1)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+108 s in the 10-1000 keV band is 8.4 +/- 0.3 ph/s/cm^2.

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