[vsnet-grb-info 18421] GRB 160820A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19869
SUBJECT: GRB 160820A: Fermi GBM observation
DATE:    16/08/26 16:27:47 GMT
FROM:    Hoi-Fung Yu at MPE  <sptfung at mpe.mpg.de>

H.-F. Yu (MPE) and C.A. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 11:54:10.65 UT on 20 August 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160820A (trigger 493386854 / 160820496),
which was also detected by the Konus-Wind (Svinkin et al., GCN 19851)
and located by the Interplanetary Network (Svinkin et al., GCN 19850).
The GBM on-ground location is consistent with the IPN position.

The angle from the Fermi LAT boresight at the GBM trigger time is 63 degrees.

The GBM light curve shows a single pulse
with a duration (T90) of about 0.4 s (50-300 keV).
The time-averaged spectrum from T0-0.064 s to T0+0.192 s is
best fit by a Band function with Epeak = 810 +/- 200 keV,
alpha = -0.7 +/- 0.1, and beta = -2.6 +/- 0.8.

The event fluence (10-1000 keV) in this time interval is
(7.7 +/- 0.4)E-07 erg/cm^2. The 64-ms peak photon flux measured
starting from T0+0.000 s in the 10-1000 keV band
is 13 +/- 1 ph/s/cm^2.

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