GCN Circular 21869
Subject
GRB 170911A: Fermi GBM observation
Date
2017-09-12T11:49:28Z (8 years ago)
From
Andreas von Kienlin at MPE <azk@mpe.mpg.de>
A. von Kienlin (MPE), R. Hamburg (UAH), and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 06:24:22.79 UT on 11 September 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170911A (trigger 526803867 / 170911267)
which was also detected by the MAXI GSC
(Takao et al. 2017, GCN 21858)
The GBM on-ground location is consistent with the MAXI position.
The angle from the Fermi LAT boresight at the GBM trigger time is 43 degrees.
The GBM light curve shows a single peak
with a duration (T90) of about 20 s (50-300 keV).
The time-averaged spectrum from T0-3.072 s to T0+4.096 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.2 +/- 0.2 and
the cutoff energy, parameterized as Epeak, is 260 +/- 120 keV
The event fluence (10-1000 keV) in this time interval is
(9.5 +/- 1.7)E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-1.79 s in the 10-1000 keV band
is 1.96 +/- 0.17 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."