[vsnet-grb-info 14725] GRB 140323A : Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16039
SUBJECT: GRB 140323A : Suzaku WAM observation of the prompt emission 
DATE:    14/03/27 07:53:42 GMT
FROM:    Tetsuya Yasuda at Saitama U  <yasuda at heal.phy.saitama-u.ac.jp>

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


The long GRB 140323A (Swift/BAT trigger #592916 ; Troja et al., GCN
16027; Sakamoto et al., GCN 16029; Fermi-GBM detection : Yu and von
Kienlin, GCN 16032; Fermi-LAT detection: Vianello et al., GCN 16034;
Konus-Wind detection : Golenetskii et al., GCN16035) triggered the
Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of
50 keV - 5 MeV at 10:23:12.262 UT (=T0).

The observed light curve shows a multi-peaked structure in two main
episodes lasting from T0-15 s to T0+95 s with a duration (T90) of about
90 seconds. The fluence in 100 - 1000 keV was 1.36 (+/- 0.12) x10^-6 erg/cm^2.
The 1-s peak flux measured from T0+6 s was 2.17 (+0.35, -0.45)
photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-10 s to
T0+95 s is well fitted in 200 keV to 5 MeV by a single power-law with a
photon index of 2.64 (+0.34, -0.28) (chi^2/d.o.f = 12.5/14).

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