[vsnet-grb-info 10762] GRB 110715A : Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  12184
SUBJECT: GRB 110715A : Suzaku WAM observation of the prompt emission
DATE:    11/07/20 02:05:47 GMT
FROM:    Norisuke Ohmori at Miyazaki U  <ohmori at astro.miyazaki-u.ac.jp>

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

The long GRB 110715A (Swift/BAT trigger #457330 ; Sonbas et al., GCN 12158) 
triggered the Suzaku Wide-band  All-sky Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV at 13:13:49.914 UT (=T0).

The observed light curve shows a multi-peaked structure starting at T0,
ending at T0+4s, followed by a weaker emission seen up to T0+20s 
with a duration (T90) of 8 seconds.
The fluence in 100 - 1000 keV was 1.28 (-0.06, +0.07) x10^-5 erg/cm^2.
The 1-s peak flux measured from T0+3s was 20.3 (-1.1, +1.0) photons/cm^2/s 
in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-3s to
T0+20s is well fitted by a single power-law with a photon index
of 2.67 (-0.18, +0.19) (chi^2/d.o.f = 24.0/15).
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/trig/grb_table.html