[vsnet-grb-info 14571] GRB 140219A: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15885
SUBJECT: GRB 140219A: Suzaku WAM observation of the prompt emission 
DATE:    14/02/27 11:42:27 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. 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 extremely bright and long-duration GRB 140219A
(localized by IPN: Hurley et al., GCN 15864;
Fermi-GBM detection: Zhang, GCN 15866; Fermi-LAT detection: Guiriec et
al., GCN 15867; Konus-Wind detection: Golenetskii et al., GCN15870;
MAXI/GSC detection: Serino et al., GCN15882) triggered the Suzaku
Wide-band All-sky Monitor (WAM) which covers an
energy range of 50 keV - 5 MeV at 19:45:57.754 UT (=T0).

The observed light curve shows a strong multi-peaked structure lasting from
T0 s to T0+3 s, followed by a weaker multi-peaked emissions
seen up to T0+27 s with a total duration (T90) of about 17 seconds.　

The fluence in 100 - 1000 keV was 1.73 (+0.06,-0.08)x10^-5 erg/cm^2. The 1-s
peak flux measured from T0+1.5 s was 83.6 (+6.5,-6.4) photons/cm^2/s in
the same energy range.

Preliminary result shows that the time-averaged spectrum from
T0 s to T0+27 s is fitted by a GRB Band model as follows.
the low-energy photon index alpha: -1.00 (+0.06,-0.11),
the high-energy photon index beta: -2.68 (+0.08,-0.11),
and the peak energy Epeak: 1930(+176,-79) keV (chi^2/d.o.f = 71.9/47).

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

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