[vsnet-grb-info 11162] GRB 111117A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  12574
SUBJECT: GRB 111117A: Fermi GBM observation
DATE:    11/11/19 15:35:30 GMT
FROM:    Suzanne Foley at MPE  <sfoley at mpe.mpg.de>

S. Foley (MPE) and P. Jenke (UAH)
report on behalf of the Fermi GBM Team:

"At 12:13:42.03 UT on 17 November 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 111117A (trigger 343224824 / 111117510)
which was also detected by the Swift/BAT
(Mangano et al. 2011, GCN 12559).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 12 degrees.
Moreover, this burst was bright enough to result in a Fermi spacecraft
autonomous rapid repoint (ARR) maneuver.

The GBM light curve consists of two pulses
with a duration (T90) of about 0.5 s (50-300 keV).
The time-averaged spectrum from T0-0.128 s to T0+0.384 s is
well fit by a power law function with an exponential high-energy cutoff.
The power law index is -0.69 (+0.17/- 0.15) and the lower limit on
the cutoff energy, parameterized as Epeak, is 370 keV.

The event fluence (10-1000 keV) in this time interval is
(6.7 +/- 0.2)E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.128 s in the 10-1000 keV band
is 2.8 +/- 0.2 ph/s/cm^2.


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