[vsnet-grb-info 17933] GRB 160503A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19380
SUBJECT: GRB 160503A: Fermi GBM observation
DATE:    16/05/04 12:34:06 GMT
FROM:    Kilian Toelge at MPE  <tkili at mpe.mpg.de>

B. Mailyan (UAH) and K. Toelge (MPE)
report on behalf of the Fermi GBM Team:

"At 13:36:32.008 UT on 03 May 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160503A (trigger 483975396 / 160503567), which 
was also detected by the LAT
(N. Omodei et al. 2016, GCN 19379)
The GBM on-ground location is consistent with the LAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 25 
degrees.

The GBM light curve consists of two peaks
with a duration (T90) of about 59.4 s (50-300 keV).
The time-averaged spectrum from T0-4.9 s to T0+28.9 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.28 +/- 0.14 and
the cutoff energy, parameterized as Epeak, is 138.7 +/- 33.5 keV.

The event fluence (10-1000 keV) in this time interval is
(2.15 +/- 0.25)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.58 s in the 8-1000 keV band
is 2.5 +/- 0.2 ph/s/cm^2.

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