GCN Circular 5462

K.Yamaoka, S.Sugita (Aoyama Gakuin U.), M.Ohno, T.Takahashi, 
T.Asano, T.Uehara, Y.Fukazawa (Hiroshima U.), Y.Terada, T.Tamagawa, 
M.Suzuki (RIKEN), K.Abe, K.Onda, M.Suzuki, M.Tashiro (Saitama U.), 
S.Hong (Nihon U.) K.Nakazawa, T.Takahashi (ISAS/JAXA), T.Enoto, 
R.Miyawaki, K.Kokubun (Univ. of Tokyo) 
on behalf of the Suzaku HXD-II team report:

The bright, long burst, GRB 060813 (Swift-BAT trigger #224364; 
Morettim et al., GCN5442
Not found
 
 
; Cummings et al. GCN 5443
Not found
 
 
), triggered 
the Suzaku Wideband All-sky Monitor (WAM) which covers an energy 
range of 50 keV - 5 MeV at 22:50:24.295 (UT). 
The observed prompt emission exhibits a single-peaked lightcurve
with a duration (T90) of 6.1 seconds. 
The fluence in 100 - 1000 keV was (1.0 +/- 0.1)X10^-6 erg/cm2. 
The 1-s peak flux was 5.6 +/- 0.2 photons/cm2/s 
in the same energy range.

Preliminary result shows that the time-averaged spectrum 
is well-fitted by a power law with an exponential 
cutoff having the following parameters:
alpha = 0.93 +- 0.31,
E0 = 229 (+82, -53) keV, and 
Epeak = 248 +- 20 keV.
All the quoted errors are at statistical 90% confidence level, 
 not included in the systematic errors.

Further detailed analyses are in progress.