[vsnet-grb-info 9252] GRB100503A: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10735
SUBJECT: GRB100503A: Suzaku WAM observation of the prompt emission
DATE:    10/05/10 09:49:44 GMT
FROM:    Yoshitaka Hanabata at Hiroshima U  <hanabata at hep01.hepl.hiroshima-u.ac.jp>

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

The long GRB 100503A (Fermi/GBM trigger #294585485; Tierney et al.,
GCN 10714) triggered the Suzaku Wide-band All-sky Monitor (WAM) which
covers an energy of 50 keV - 5 MeV at 2010-05-03 13:18:51.17 UT (T=0).

The observed light curve shows a multi-peaked structure lasting from
T0-51s to T0+89s with T90 of about 103 seconds. The fluence in 100 -
1000 keV was 8.56 (-2.58, +2.10)x10^-6 erg/cm^2. The 1-s peak flux
measured from T0-1s was 1.23 (-0.27, +0.24) photons/cm^2/s in the
same energy range.

Preliminary result shows that the time-averaged spectrum from T0-51s
to T0+89s is well fitted by a single power-law with a photon index
of 2.04 (-0.29, +0.36) (chi^2/d.o.f = 11.1/11).

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

The light curves for this burst wiil be available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html