[vsnet-grb-info 8703] GRB 091127: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10204
SUBJECT: GRB 091127: Fermi GBM detection
DATE:    09/11/28 22:01:05 GMT
FROM:    Colleen A. Wilson at NASA/MSFC/NSSTC  <colleen.wilson at nasa.gov>

Colleen A. Wilson-Hodge (NASA/MSFC) and Robert D. Preece (UAH)
report on behalf of the Fermi GBM Team:

"At 23:25:45.48 UT on 27 November 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 091127 (trigger 281057147 / 091127976), which was
also detected by the SWIFT-BAT (Troja et al. 2009, GCN 10191)
The GBM on-ground location is consistent with the Swift position.
 
The angle from the Fermi LAT boresight is 25 degrees.

The GBM light curve consists of three peaks
with a duration (T90) of about 9 s (8-1000 keV).
The time-averaged spectrum from T0+0.002 s to T0+9.984 s is
adequately fit by a Band function with Epeak = 36 +/- 2 keV,
alpha = -1.27 +/- 0.06, and beta = -2.20 +/- 0.02
(chi squared 645.8 for 445 d.o.f.).

The event fluence (8-1000 keV) in this time interval is
(1.87 +/- 0.02)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1 s in the 8-1000 keV band
is 46.9 +/- 0.9 ph/s/cm^2.

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