[vsnet-grb-info 19441] GRB 170511A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21161
SUBJECT: GRB 170511A: Fermi GBM observation
DATE:    17/05/29 14:00:55 GMT
FROM:    Elisabetta Bissaldi at U.Innsbruk/IAPP  <Elisabetta.Bissaldi at uibk.ac.at>

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


"At 05:59:11.92 UT on 11 May 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170511A (trigger 516175156 / 170511249),
which was also detected by MAXI/GSC (Takao et al. 2017, GCN 21137)
and by the CALET GBM (Yamaoka et al. 2017, GCN 21146).
The GBM on-ground location is consistent with the MAXI position.
The angle from the Fermi LAT boresight at the GBM trigger time is 85 degrees.

The GBM light curve consists of multiple peaks
with a duration (T90) of about 40 s (50-300 keV).
The time-averaged spectrum from T0 to T0+40 s is
best fit by a Band function with Epeak = 82 +/- 3 keV,
alpha = -0.90 +/- 0.03, and beta = -2.41 +/- 0.05.
The event fluence (10-1000 keV) in this time interval is
(2.80 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+34.5 s in the 10-1000 keV bandbis 30.1 +/- 0.5 ph/s/cm^2.


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