[vsnet-grb-info 12973] GRB 130310A : Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14310
SUBJECT: GRB 130310A : Suzaku WAM observation of the prompt emission
DATE:    13/03/15 10:55:37 GMT
FROM:    Masanori Ohno at Hiroshima U  <ohno at hep01.hepl.hiroshima-u.ac.jp>

T. Kawano, M. Ohno, Y. Hanabata, Y. Tanaka, R. Nakamura, K. Takaki,
Y. Fukazawa (Hiroshima U.),
A. Sakamoto, M. Tashiro, Y. Terada, W. Iwakiri, T. Yasuda, K. Takahara,
M. Asahina, S. Kobayashi, H. Ueno (Saitama U.),
M. Akiyama, N. Ohmori,  M. Yamauchi (Univ. of Miyazaki),
Y. E. Nakagawa (Waseda U.), S. Sugita (Nagoya U.), K. Yamaoka,
M. Kokubun, T. Takahashi (ISAS/JAXA), Y. Urata, P. Tsai (NCU), K. Nakazawa,
K. Makishima (Univ. of Tokyo), on behalf of the Suzaku WAM team, report:

The bright short GRB (Fermi-LAT detection ; Guiriec et al., GCN14282;
Sbarufatti et al., GCN 14288) triggered by the Suzaku Wide-band All-sky
Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV at 20:09:45 UT (=T0).

The observed light curve shows a single peak structure starting at
T0 s, ending at T0+1 s with a duration (T90) of about 0.3 seconds.
The fluence in 100 - 1000 keV was 7.78 (-1.13, +2.72) x 10^-6 erg/cm^2.
The 1-s peak flux measured from T0 s was 14.34(-1.37,+2.30)
photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0 to
T0+1 s is well fitted by GRB Band model:
the low-energy photon index alpha: -1.13 (-0.25, +0.16),
                      beta        : -2.07 (-0.32, +0.19)
and the peak energy Epeak: 1000 (-442, +639) keV (chi^2/d.o.f = 43.2/44).
All the quoted errors are at statistical 90% confidence level.

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