W. Iwakiri(RIKEN), M. Tashiro, Y. Terada, T. Yasuda, Y. Ishida, H. Ueno,
S. Sugimoto (Saitama U.),
M. Ohno, K. Takaki, T. Kawano, R. Nakamura, S. Furui, Y. Fukazawa
M. Yamauchi, N. Ohmori, M. Akiyama (Univ. of Miyazaki),
K. Yamaoka (Nagoya U.), S. Sugita (Ehime U.), Y. E. Nakagawa, M. Kokubun,
T. Takahashi (ISAS/JAXA), Y. Hanabata (ICRR),
Y. Urata (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo)
on behalf of the Suzaku WAM team, report:
The long, IPN localized GRB 130521B (Hurley et al., GCN 14696;
Konus-Wind detection : Golenetskii et al., GCN 14698) triggered the
Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of
50 keV - 5 MeV at 21:24:31.599 UT (=T0).
The observed light curve shows a multi-peaked structure starting at
T0-0s, ending at T0+25 s with a duration (T90) of about 23 seconds. The
fluence in 100 - 1000 keV was 1.21 (+0.07/-0.08) x 10^-5 erg/cm^2. The
1-s peak flux measured from T0+1 s was 4.25 (+1.63/-0.54) photons/cm^2/s
in the same energy range.
Preliminary result shows that the time-averaged spectrum from T0-0s to
T0+25 s is well fitted by a single power-law with a photon index of 2.33
(+0.19/-0.16) (chi^2/d.o.f = 30.0/25).
All the quoted errors are at statistical 90% confidence level,in which
the systematic uncertainties are not included.
The light curves for this burst are available at: