GCN Circular 20943
Subject
GRB 170329A: Fermi GBM detection
Date
2017-03-30T04:07:55Z (8 years ago)
From
Oliver J Roberts at USRA/NASA <oliver.roberts@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."