[vsnet-grb-info 15465] GRB 140828A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16754
SUBJECT: GRB 140828A: Fermi GBM observation
DATE:    14/08/29 07:52:08 GMT
FROM:    Andreas von Kienlin at MPE  <azk at mpe.mpg.de>

A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team:

"At 06:54:12.18 UT on 28 August 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 140828A (trigger 430901655 / 140828288), which
was also detected by the Swift/BAT (Melandri et al. 2014, GCN 16751)
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight is 57 degrees.

The GBM light curve consists of a single pulse
with a duration (T90) of about 24 s (50-300 keV).
The time-averaged spectrum from T0-6.1 s to T0+16.4 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.5 +/- 0.1  and
the cutoff energy, parameterized as Epeak, is 140 +/- 30 keV.

The event fluence (10-1000 keV) in this time interval is
(3.5 +/- 0.2)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+2.43 s in the 10-1000 keV band
is 3.5 +/- 0.2  ph/s/cm^2.

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