[vsnet-grb-info 3628] GRB 060813: A long, bright GRB detected with Suzaku WAM

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5462
SUBJECT: GRB 060813: A long, bright GRB detected with Suzaku WAM
DATE:    06/08/16 20:18:47 GMT
FROM:    Masanori Ohno at Hiroshima U  <ohno at hirax7.hepl.hiroshima-u.ac.jp>

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; Cummings et al. GCN 5443), 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.