[vsnet-grb-info 16694] GRB 150627A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17975
SUBJECT: GRB 150627A: Fermi GBM observation
DATE:    15/06/27 16:03:39 GMT
FROM:    Hoi-Fung Yu at MPE  <sptfung at mpe.mpg.de>

H.-F. Yu (MPE), E. Burns, V. Connaughton, A. Goldstein (UAH), and M. Gibby (Jacobs)
report on behalf of the Fermi GBM Team:

"At 04:23:23.68 UT on 27 June 2015, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 150627A (trigger 457071806 / 150627183),
which was also detected by the Fermi LAT (Arimoto et al., GCN 17971).
The GBM on-ground location is consistent with the LAT position.

The GBM trigger resulted in an Autonomous Repoint Request (ARR) 
that was accepted and the spacecraft slewed to the GBM in-flight 
location. At the GBM trigger time, the angle of the LAT localization 
to the LAT boresight is 75 deg.

The GBM light curve consists of multiple pulses
with a duration (T90) of about 65 s (50-300 keV).
The time-averaged spectrum from T0-3.072 s to T0+92.161 s is
best fit by a Band function with Epeak = 233 +/- 5 keV,
alpha = -1.04 +/- 0.01, and beta = -2.18 +/- 0.02.

The event fluence (10-1000 keV) in this time interval is
(1.90 +/- 0.01)E-4 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+59.521 s in the 10-1000 keV band
is 65.2 +/- 0.6 ph/s/cm^2.

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