[vsnet-grb-info 6607] GRB 080905C: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8213
SUBJECT: GRB 080905C: Fermi GBM detection
DATE:    08/09/11 15:08:30 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs at mpe.mpg.de>

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



"At 13:41:29 UT on 5 September 2008, the Fermi Gamma-ray Burst Monitor  
triggered and located GRB 080905C (trigger 242314890 / 080905570).
The on-ground calculated location, using the Fermi GBM trigger 
data, is RA = 96.9, Dec = -69.8 (J2000 degrees) 
(equivalent to J2000 06h 28m, -69d 48'), 
with a statistical uncertainty of 8 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 108 degrees. 

This event comprises three pulses beginning at T0-4 s. 
The main emission occurs during the first 11 sec and T90 (50-300 keV)
is about 28 s. The time-averaged spectrum from T0-3.6 s to T0+17 s
is adequately fit by a power law function with an exponential
high energy cutoff. The power law index is -0.90 +/-0.17 and
the cutoff energy, parameterized as Epeak, is 78.8 +/- 5.9 keV.

The fluence (25-1000 keV) is 4.6 (+/-0.3)E-06  erg/cm2
and the peak flux (25-1000 keV) on the 128 ms timescale 
is 4.4 +/- 1.9 ph/cm2/s.


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