[vsnet-grb-info 15210] GRB 140619C: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16502
SUBJECT: GRB 140619C: Suzaku WAM observation of the prompt emission
DATE:    14/07/02 10:55:03 GMT
FROM:    Kazutaka Yamaoka at Nagoya U  <yamaoka at stelab.nagoya-u.ac.jp>

W. Iwakiri (RIKEN), M. Tashiro, Y. Terada, T. Yasuda, S. Koyama, S. Takeda,
T. Nagayoshi, J. Enomoto, S. Nakaya, T. Fujinuma, S. Matsuoka (Saitama U.),
M. Yamauchi, N. Ohmori, R. Kinoshita (Univ. of Miyazaki),
M. Ohno, T. Kawano, 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 bright GRB 140619C (localized by IPN: Hurley et al., GCN 16427;
Konus-Wind detection: Golenetskii et al., GCN 16429) triggered the Suzaku
Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV -
5 MeV at UT 22:46:01.623 (=T0).

The observed light curve shows a multi-peaked structure, consisting of
two separated episodes: the first one lasting from T0 to T0+6 s, and the
second brighter one lasting from T0+70 s to T0+94 s,  with a total 
duration (T90) of about 87 seconds. The fluence in 100 - 1000 keV was 
4.34 (+0.21, -0.23)x10^-5 erg/cm^2. The 1-s peak flux measured from 
T0+75 s was 8.32 (+1.12, -1.17) photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0 to
T0+92 s is well fitted by a single power-law with a photon index of 2.50
(+0.15, -0.14) (chi^2/d.o.f = 15.4/14).

All the quoted errors are at statistical 90% confidence level.
There might be some calibration uncertainties in spectral parameters
since the GRB photons came through the X-ray micro-calorimeter (XRS) dewar.

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