[vsnet-grb-info 10546] GRB 110422A: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  11976
SUBJECT: GRB 110422A: Suzaku WAM observation of the prompt emission 
DATE:    11/04/26 11:08:37 GMT
FROM:    Masanori Ohno at ISAS/JAXA  <ohno at astro.isas.jaxa.jp>

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

The bright GRB 110422A (Swift/BAT trigger #451901 ; Mangano et al., GCN
11957; Palmer et al., GCN 11959) triggered the Suzaku Wide-band All-sky
Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 15:41:45
UT (=T0).

The observed light curve shows a multi-peaked structure starting at
T0-2s, ending at T0+35s with a duration (T90) of about 22 seconds. The
fluence in 100 - 1000 keV was 3.60 (+/- 0.14) x10-5 erg/cm2.
The 1-s peak flux measured from T0+18s was 14.5 (+/- 0.9) photons/cm2/s
in the same
energy range.

Preliminary result shows that the time-averaged spectrum from T0-2s to
T0+35s is well fitted by a single power-law with a photon index
of 2.83 (+/- 0.11) (chi2/d.o.f = 21.3/14).
All the quoted errors are at statistical 90% confidence level.


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