[vsnet-grb-info 6896] GRB 081101B: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8486
SUBJECT: GRB 081101B: Fermi GBM detection
DATE:    08/11/06 12:17:16 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs at mpe.mpg.de>

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


"At 12:45:24.08 UT on November 01, 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081101B (trigger 247236325 / 081101532).
The on-ground calculated location, using the Fermi GBM
trigger data, is RA = 212.5 deg, Dec = -31.1 deg
(equivalent to J2000 14h 10m, -31d 06'), with a statistical
uncertainty of 1.9 degrees (radius, 1-sigma containment;
there is additionally a systematic error which is currently
estimated to be 2 to 3 degrees). The angle from the
Fermi LAT boresight is 116 degrees.

This GRB consists of one main emission phase comprising
several overlapping pulses, with an estimated T90 (8-1000 keV)
of about 8 s and T50 (8-1000 KeV) of about 5 s.
The time-averaged spectrum from T0 to T0+7.680 s
is best fit by a power law function with an exponential
high energy cutoff. The power law index is -0.62 +/- 0.05
and the cutoff energy, parameterized as Epeak,
is 550 +/- 30 keV. The event fluence (8-1000 keV)
in this time interval is (1.60 +/- 0.03)E-05 erg/cm^2.
The 1-sec photon flux measured starting from T0+1.536 s
in the 8-1000 keV band is 10.3 +/- 0.3 ph/s/cm^2.


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