GCN Circular 19587

E. Burns (UAH) reports on behalf of the Fermi GBM Team:

"We report temporal and spectral analysis on GRB 160625B, covering
all three Fermi trigger times (LAT trigger 488587408 / 160625947
GBM triggers 488587220 / 160625945 and 488587880 / 160625952).
All times are relative to the first GBM trigger time.

The GBM light curve consists of multiple peaks
with a total duration (T90) of about 460 s (50-300 keV).
The 1.024-sec peak photon flux of the main peak measured starting
from T0+188.707 s in the 10-1000 keV band is 167 +/- 1 ph/s/cm^2.

The soft peak that initially triggered GBM is about 1 second long.
The time-averaged spectrum from T0+0.002 s to T0+1.056 s is
well fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.2 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 68 +/- 1 keV.
The event fluence (10-1000 keV) in this time interval is
(1.65 +/- 0.03)E-06 erg/cm^2.

The main peak that triggered the LAT is about 25 seconds long.
The time-averaged spectrum from T0+187.427 s to T0+212.003 s is
well fit by a Band function with Epeak = 657 +/- 5 keV,
alpha = -0.74 +/- 0.00, and beta = 2.36 +/- 0.01.
The event fluence (10-1000 keV) in this time interval is
(5.00 +/- 0.01)E-04 erg/cm^2.

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