[vsnet-grb-info 19252] GRB 170329A: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20943
SUBJECT: GRB 170329A: Fermi GBM detection
DATE:    17/03/30 04:07:55 GMT
FROM:    Oliver J Roberts at USRA/NASA  <oliver.roberts at nasa.gov>

E.Bissaldi (Politecnico & INFN Bari), O.J.Roberts (USRA/MSFC) 
and C.Meegan (UAH) report on behalf of the Fermi GBM Team:

"At 09:17:06.94 UT on 29 March 2017, the Fermi Gamma-Ray Burst Monitor 
triggered and located GRB 170329A (trigger 512471831 / 170329387),
which was also detected by the LAT (Yassine et al. 2017, GCN 20942)
The GBM on-ground location is consistent with the LAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 33 degrees.

The GBM light curve consists of a bright peak
with a duration (T90) of 33.5 s (50-300 keV).
The time-averaged spectrum from T0+0 s to T0+33.5 s is 
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.61 +/- 0.06 and
the cutoff energy, parameterized as Epeak, is 799 +/- 86 keV

The event fluence (10-1000 keV) in this time interval is
(1.45 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.3 s in the 10-1000 keV band
is 5.2 +/- 0.2 ph/s/cm^2.

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