[vsnet-grb-info 17429] GRB 160107A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18844
SUBJECT: GRB 160107A: Fermi GBM observation
DATE:    16/01/08 14:23:48 GMT
FROM:    Peter Veres at UAH  <veresp at gmail.com>

P Veres (UAH) and C Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 2016-01-07 22:20:41.50 UT on 7 January 2016, the Fermi Gamma-Ray
Burst Monitor
triggered and located GRB 160107A (trigger 473898045 / 160107931), which
was also detected by the MAXI/GSC (Nakagawa et al., GCN 18839).
The GBM on-ground location is consistent with the MAXI position.

The trigger resulted in an Autonomous Repoint Request (ARR)
by the GBM Flight Software owing to the high peak flux
of the GRB. This ARR was accepted and the spacecraft slewed to the GBM in-flight
location. The initial angle from the Fermi LAT boresight to
the best location is 62 degrees.

The GBM light curve consists of multiple peaks
with a duration (T90) of about 114 s (50-300 keV).
The time-averaged spectrum from T0-0.5 s to T0+110 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.79 +/- 0.02 and
the cutoff energy, parameterized as Epeak, is 54.5 +/- 2.6 keV.

The event fluence (10-1000 keV) in this time interval is
(3.63 +/- 0.06)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+27.7 s in the 10-1000 keV band
is 16.8 +/- 0.3 ph/s/cm^2.

A Band function fits the spectrum equally well
with Epeak = 50.8 +/- 3.1 keV, alpha = -1.75 +/- 0.03 and beta = -2.47 +/- 0.14.

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