GCN Circular 12152

Y. Hanabata, T. Uehara, T. Takahashi, M. Mizuno, M. Ohno, Y. Fukazawa
(Hiroshima U.), T. Yasuda, Y. Terada, M. Tashiro, W. Iwakiri,
K. Takahara (Saitama U.), S. Sugita (Nagoya U.), K. Yamaoka (Aoyama
Gakuin U.), M. Kokubun, T. Takahashi (ISAS/JAXA), Y. E. Nakagawa (Waseda U.),
N. Ohmori, M. Akiyama, M. Yamauchi (Univ. of Miyazaki), Y. Urata,
P. Tsai, C-J. Chuang (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo),
on behalf of the Suzaku WAM team, report:

The bright long GRB110709A (Swift/BAT trigger #456939, GCN 12118
Not found
 
 
;
Holland et al.) triggered the Suzaku Wide-band All-sky Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV at 15:24:27.951 UT (=T0).

The observed light curve shows multiple peaks starting at T0 s, ending
at T0+45 s, with a duration (T90) of about 41.5 seconds. The fluence in
100 - 1000 keV was 2.02 (-0.26, +0.10) x 10^-5 erg/cm^2. The 1-s peak
flux measured from T0+7 s was 4.10 (-0.96, +0.10) photons/cm^2/s in the
same range.

Preliminary result shows that the time-averaged spectrum from T0 s to
T0+45 s is well fitted by a power-law with exponential cutoff model:
 dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
 alpha       1.37 (-0.61, +0.49), and
 Epeak       431 (-113, +173) keV (chi^2/d.o.f. = 18.0/12).

We also shows the results with the same spectrum fitted by a GRB Band
model fixing beta of 2.5,
the low-energy photon index alpha: 1.34 (-0.49, +0.74)
and the peak energy Epeak: 407 (-96, +158) keV (chi^2/d.o.f = 17.4/12). 
All the quoted errors are at statistical 90% confidence level.

The light curves for this burst are available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html