[vsnet-grb-info 14670] GRB140308A: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15984
SUBJECT: GRB140308A: Suzaku WAM observation of the prompt emission
DATE:    14/03/15 08:46:38 GMT
FROM:    Makoto Tashiro at Saitama U/Swift  <tashiro at phy.saitama-u.ac.jp>

T. Nagayoshi, M. Tashiro, Y. Terada, S. Koyama, T. Yasuda, S. Takeda,
Y.　Ishida, H. Ueno, S. Sugimoto (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),
W. Iwakiri (RIKEN), Y. Hanabata (ICRR), Y. Urata (NCU), K. Nakazawa,
K. Makishima (Univ. of Tokyo) on behalf of the Suzaku WAM team, report:

The long GRB 140308A (Konus-Wind detection: S. Golenetskii et al.,
GCN 15943, IPN localization: S. Golenetskii et al., GCN 15941)
was triggered the Suzaku Wide-band All-sky Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV at 03:49:26.030 UT (=T0).

The observed light curve shows a multi-peaked structure starting at 
T0-10 s, ending at T0+80 s with a duration (T90) of about 64 seconds.
The fluence in 100 - 1000 keV was 4.02 (-0.78, +0.14) x10^-5 erg/cm^2.
The 1-s peak flux measured from T0+20 s was
7.71 (-5.71, +0.07) photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-10 s
to T0+80 s is well fitted by a GRB Band model in 90 keV to 5 MeV.
the low-energy photon index alpha: -0.95 (-0.44, +1.11),
the high-energy photon index beta: -2.20 (-0.23, +0.14),
and the peak energy Epeak: 386 (-128, +132) keV
(chi^2/d.o.f = 24.9/25).

Due to the brightness of this burst, a 3% systematic error was added for
low energy channels. 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