[vsnet-grb-info 14285] GRB 131216A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15599
SUBJECT: GRB 131216A: Fermi GBM observation
DATE:    13/12/17 01:59:46 GMT
FROM:    Veronique Pelassa at UAH  <vero.pelassa at gmail.com>

V. Pelassa (UAH) reports on behalf of the Fermi GBM Team:

"At 01:56:32.06  UT on 16 December 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 131216A (trigger 408851795 / 131216081).
It was also detected by the Fermi Large Area Telescope (Veres et al 2013,
GCN 15598).

The on-ground calculated location, using the GBM trigger data, is
RA = 91.6, DEC = -35.5 (J2000 degrees, equivalent to +06h 06m, -35d 30'),
with an uncertainty of 2.7 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 was
44 degrees at trigger time, then an autonomous repoint maneuver placed the
GRB near the center of the LAT field-of-view.

This burst was also independently detected by INTEGRAL SPI-ACS.

The GBM light curve consists of a single FRED pulse
with a duration (T90) of about 24 s (50-300 keV).
The time-averaged spectrum from T0-0.256 s to T0+11.264 s, when the flux is
highest, is best fit by a Band function with Epeak = 359 +/- 40 keV,
alpha = -0.64 +/- 0.07, and beta = -2.03 +/- 0.13
(Castor statistics 777.70 for 716 d.o.f.).

The event fluence (10-1000 keV) in this time interval is
(8.60 +/- 0.20)E-06  erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+0.512 s in the 10-1000 keV band
is 7.9 +/- 0.2 ph/s/cm^2.

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