[vsnet-grb-info 18648] GRB 161022A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20096
SUBJECT: GRB 161022A: Fermi GBM observation
DATE:    16/10/22 16:33:18 GMT
FROM:    Oliver Roberts at UCD/Fermi  <oliver.roberts at ucd.ie>

O.J. Roberts (UCD) reports on behalf of the Fermi GBM Team:

At 02:43:45.92 UT on October 22nd, 2016, the Fermi Gamma-Ray
Burst Monitor triggered and located GRB 161022A
(trigger 498797029/161022114), which was also detected by Swift
(Stamatikos et al., GCN 20087). The GBM on-ground location is
consistent with the Swift position. The angle from the Fermi LAT
boresight is 131 degrees.

The GBM light curve shows a weak, FRED-like peak with a duration
(T90) of about 19 s (50-300 keV). The time-averaged spectrum
from T0-6.1 s to T0+11.3 s is adequately fit by a power law function
with an exponential high-energy cutoff. The power law index is
-0.59 +/- 0.37 and the cutoff energy, parameterized as Epeak,
is 155.7 +/- 33.2 keV

The event fluence (10-1000 keV) in this time interval is
(1.65 +/- 0.24)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-1.3 s in the 10-1000keV band is 2.5 +/- 0.4 ph/s/cm^2.

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