[vsnet-grb-info 18484] GRB 160917A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19932
SUBJECT: GRB 160917A: Fermi GBM observation
DATE:    16/09/18 00:33:54 GMT
FROM:    Peter Veres at UAH  <veresp at gmail.com>

P Veres (UAH), A von Kienlin (MPE) and C Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 11:30:19.286 UT on 17 September 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160917A (trigger 495804623 / 160917479).
which was also detected by the Swift/BAT
​ ​
(Racusin et al., GCN 19926).
​ ​
The GBM on-ground location is consistent with the Swift position.


The angle from the Fermi LAT boresight at the GBM trigger time is 46
degrees.


The GBM light curve consists of a single peak
with a duration (T90) of about 47 s (50-300 keV).
The time-averaged spectrum from T0 to T0+14.1 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.00 +/- 0.05 and
the cutoff energy, parameterized as Epeak, is 1604 +/- 357 keV.


The event fluence (10-1000 keV) in this time interval is
(7.2 +/- 0.3)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0 in the 10-1000 keV band
is 5.1 +/- 0.2 ph/s/cm^2.

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