[vsnet-grb-info 13187] GRB 130425A: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14524
SUBJECT: GRB 130425A: Suzaku WAM observation of the prompt emission
DATE:    13/05/02 04:34:53 GMT
FROM:    Norisuke Ohmori at Miyazaki U  <ohmori at astro.miyazaki-u.ac.jp>

M. Akiyama, M. Yamauchi, N. Ohmori (Univ. of Miyazaki),
M. Ohno, K. Takaki, T. Kawano, R. Nakamura, S. Furui, Y. Fukazawa
(Hiroshima U.),
M. Tashiro, Y. Terada, T. Yasuda, Y. Ishida, H. Ueno, S. Sugimoto (Saitama U.),
K. Yamaoka (Nagoya U.),  S. Sugita (Ehime U.), Y. E. Nakagawa, M. Kokubun,
T. Takahashi (ISAS/JAXA), W. Iwakiri(RIKEN), Y. Hanabata (ICRR), Y. Urata
(NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo) on behalf of the Suzaku
WAM team, report:

The long GRB 130425A (Fermi-GBM detection: von Kienlin, GCN 14442;
IPN localization: Hurley et al., GCN14446) triggered by the 
Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of
50 keV - 5 MeV at 07:51:22.243 UT (=T0).

The observed light curve shows a weak initial single peak from T0-2s to 
T0-1s and multi-peaked structure starting from T0+30s from T0+61s,
with a duration (T90) of about 61 seconds.
The fluence in 100 - 1000 keV was 2.74(+0.12/-0.18) x 10^-5^  erg/cm^2^ .
The 1-s peak flux measured from T0+37s was 6.51(+0.96/-1.26) photons/cm^2/s
in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-2s to
T0+61s is well fitted by a single power-law with a photon index of
2.41 (+0.19/-0.17) (chi^2/d.o.f = 14.7/14).

All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.

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