[vsnet-grb-info 9354] GRB 100606A: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10836
SUBJECT: GRB 100606A: Suzaku WAM observation of the prompt emission
DATE:    10/06/12 16:46:30 GMT
FROM:    Satoshi Sugita at Aoyama Gakuin U.  <sugita at phys.aoyama.ac.jp>

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

The long GRB 100606A (Swift/BAT trigger #10824; Oates et al.,)
triggered the Suzaku Wide-band  All-sky Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV at 19:12:41.766 UT (=T0).

The observed light curve shows a multi-peaked structure
lasting from T0-2s to T0+100s with a duration  (T90) of about 65 seconds.
The fluence in 100 - 1000 keV was 2.21 (-0.28, +0.17) x10^-5 erg/cm^2.
The 1-s peak flux measured from T0+1s was 3.40 (-0.41 +0.28)  photons/cm^2/s
in the same energy range.

Preliminary result shows that the time-averaged spectrum from
T0 to T0+65s is well fitted by a power-law with exponential cutoff model:
dN/dE =  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
alpha       0.63 (-0.30 +0.25), and
Epeak      767 (-121 +172)  keV (chi^2/d.o.f. = 45.2/52).

All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.

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