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GCN Circular 4297

GRB051008: Suzaku WAM observation of the prompt emission
2005-11-22T12:06:55Z (18 years ago)
Masanori Ohno at Hiroshima U <>
M.Ohno, T.Takahashi, Y.Fukazawa (Hiroshima U.), 
K.Yamaoka, S.Sugita (Aoyama Gakuin U.),
Y.Terada (RIKEN), K.Abe, Y.Endo, S.Hong, K.Onda,
M.Tashiro (Saitama U.), K.Nakazawa, G.Sato,
T.Takahashi (ISAS/JAXA), R.Miyawaki,
M.Kokubun, K.Makishima (Univ. of Tokyo) and the HXD-II team

  The GRB 051008 prompt emission (Swift-BAT trigger #158855; 
Marshall et al., GCN 4069, Parsons et al., GCN 4075, Barthelmy et al.,
GCN 4077) triggered Suzaku Wideband All-sky Monitor (WAM), 
which covers an energy band of 50 keV - 5 MeV at 16:33:18 UT. 

The light curve shows two peaks with total duration about 48.2 sec. 
This is consistent with Swift observation (GCN4069). 

We performed the time-averaged spectral analysis 
using the position information provided by Swift (Marshall et al., GCN 4069). 
We found that the emission extends up to at least 2 MeV. 
The cutoff power law model provided a good fit. 
In the preliminary results, the photon index was 1.24 (+0.13 -0.15) 
and the cutoff energy was 1535 (+1419 -561) keV.  
The peak flux on 1 sec time scale was 4.1 (+0.3 -0.3) photons/s/cm^2 
(100 keV - 2 MeV) and the fluence was 3.2 (+0.2 -0.2)e-5 erg/cm^2
(100 keV - 2 MeV). The errors are at the statistical 90 % confidence level.
Systematic errors, such as the flux calibration uncertainties of
about 20%, are not included in the errors.

You can see the detail information about the instrument of WAM and
the lightcurve in the Web site

Further analysis and the refinement is in progress.
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