[vsnet-grb-info 3248] GRB 060429: Suzaku WAM observation

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5083
SUBJECT: GRB 060429: Suzaku WAM observation
DATE:    06/05/06 17:40:38 GMT
FROM:    Masanori Ohno at Hiroshima U  <ohno at hirax7.hepl.hiroshima-u.ac.jp>

M. Ohno, T. Takahashi, Y. Fukazawa (Hiroshima U.), 
K. Yamaoka, S. Sugita (Aoyama Gakuin U.), 
Y. Terada, T. Tamagawa (RIKEN), S. Hong (Nihon U.), 
K. Abe, Y. Endo, K. Onda, M. Tashiro (Saitama U.), 
G. Sato, K. Nakazawa, T. Takahashi (ISAS/JAXA), 
R. Miyawaki, M. Kokubun, K. Makishima (Univ. of Tokyo) 
and the HXD-II team report: 

The short hard burst, GRB 060429 (Hurley et al., GCN 5039,  
Golenetskii et al., GCN 5067), triggered the Suzaku 
Wide-band All-sky Monitor (WAM) which is sensitive to an 
energy band of 50 keV - 5 MeV at 12:19:51 (UT). 
The observed light curve shows a single-peak structure
with a duration (T90) of 0.11 seconds. 
The fluence in 100 - 1000 keV was 1.97 +- 0.17 X10^-6 erg/cm2. 
The 1-sec peak flux was 3.2 +- 0.3 photons/cm2/sec 
in the same energy range.

Preliminary result shows that the time-averaged spectrum 
is well fitted by a single power law with a photon index 
of 1.07 +- 0.13.

All the quoted errors are at statistical 90% confidence level.
The WAM in-flight calibration is still under way, and systematic 
errors, such as the flux calibration uncertainties of about 20%, 
are not included in the errors.

The WAM light curve of this event is available at 
http://www.astro.isas.ac.jp/suzaku/research/HXD-WAM/WAM-GRB/grb/grb_table.html

Further detailed analysis and the refinement are in progress.