[vsnet-grb-info 6904] GRB 081107: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8494
SUBJECT: GRB 081107: Fermi GBM detection
DATE:    08/11/07 15:51:17 GMT
FROM:    Andreas von Kienlin at MPE  <azk at mpe.mpg.de>

A. von Kienlin (MPE) and E. Bissaldi (MPE) 
report on behalf of the Fermi GBM Team: 

"At 07:42:01.11 UT on 07 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081107 (trigger 247736522 / 081107321).
The on-ground calculated location, using the GBM trigger 
data, is RA = 47.7, DEC = +17.0 (J2000 degrees, 
equivalent to 03h 11m, 17d 00'), with an uncertainty 
of 4.3 degrees (radius, 1-sigma containment, 
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees). 
The angle from the Fermi LAT boresight is 52 degrees.

The GBM light curve shows one major structured peak
with a duration (T90) of about 2.2 s (8-1000 keV). 
The time-averaged spectrum from T0-0.201 s to T0+1.655 s is 
best fit by a Band function with Epeak = 65 +/- 3 keV, 
alpha = 0.25 +/- 0.17, and beta = -2.80 +/- 0.15 
(chi squared 542 for 481 d.o.f.).
The event fluence (8-1000 keV) in this time interval is 
(1.64 +/- 0.28)E-06 erg/cm^2. The 1-sec photon flux measured 
starting from T0-0.073 s in the 8-1000 keV band 
is 11 +/- 3 ph/s/cm^2.

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