[vsnet-grb-info 13352] GRB 130515A: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14688
SUBJECT: GRB 130515A: Suzaku WAM observation of the prompt emission
DATE:    13/05/21 14:13:58 GMT
FROM:    Masanori Ohno at Hiroshima U  <ohno at hep01.hepl.hiroshima-u.ac.jp>

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
(Hiroshima U.),
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 short GRB 130515A (Swift/BAT trigger #555880 ; Malesani et al., GCN
14650; Barthelmy et al., GCN 14658; Fermi-GBM detection: Jenke, GCN
14663; Konus-Wind detection : Golenetskii et al., GCN 14668) triggered
the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range
of 50 keV - 5 MeV at UT 01:21:17.679 (=T0).

The observed light curve shows a single peak starting at T0+0.1 s,
ending at T0+0.4 s with a duration (T90) of about 0.25 seconds. The
fluence in 100 - 1000 keV was 1.48 (+1.67 / -0.99) x 10-6 erg/cm2.
The 1-s peak flux measured from T0+0 s was 1.4 (+0.4/-0.8)
photons/cm2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0+0 s to
T0+0.5 s is well fitted by a single power-law with a photon index of
2.17 (+0.53/-0.36) (chi2/d.o.f = 36.6/25).

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:

http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html