[vsnet-grb-info 7134] GRB 081222: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8715
SUBJECT: GRB 081222: Fermi GBM observation
DATE:    08/12/23 16:28:19 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs at mpe.mpg.de>

E.Bissaldi (MPE) and S. McBreen (UCD/MPE)
report on behalf of the Fermi GBM Team: 


"At 04:54:00.25 UT on 22 December 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081222 (trigger 251614441 / 081222204),
which was also detected by the Swift-BAT (Grupe et al., GCN Circular 8691
and Fenimore et al., GCN Circular 8709).
 
The angle from the Fermi LAT boresight is 50 degrees.

This burst was also independently detected by INTEGRAL SPI-ACS.

The GBM light curve consists of a main pulse with a
duration (T90) of about 30 s (8-1000 keV) and T50
of about 10 s (8-1000 keV). 

The time-averaged spectrum from T0 to T0+11.52 s is 
best fit by a Band function with Epeak = 134 +/- 9,
alpha = -0.55 +/- 0.07 and beta  = -2.10 +/- 0.06.

The event fluence (8-1000 keV) in this time interval is 
(1.35 +/- 0.08)E-05 erg/cm^2. The 1-sec peak photon flux 
measured starting from T0+3.3 s in the 8-1000 keV band
is 14.8 +/- 1.4 ph/s/cm^2.


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