GCN Circular 9993
Subject
GRB 090929B: Suzaku WAM observation of the prompt emission
Date
2009-10-05T09:02:34Z (15 years ago)
From
Norisuke Ohmori at Miyazaki U <ohmori@astro.miyazaki-u.ac.jp>
N. Ohmori, E. Sonoda, K. Kono, H. Hayashi, A. Daikyuji,
Y. Nishioka, K. Noda, M. Yamauchi (Univ. of Miyazaki),
K. Yamaoka (Aoyama Gakuin U.), Y. Hanabata, T. Uehara,
T. Takahashi, Y. Fukazawa (Hiroshima U.), M. Ohno, M. Suzuki,
M. Kokubun, T. Takahashi (ISAS/JAXA), W. Iwakiri, M. Tashiro,
Y. Terada, A. Endo, K. Onda, T. Sugasahara (Saitama U.),
Y. Urata (NCU), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo),
Y. E. Nakagawa, T. Tamagawa (RIKEN), S. Hong (Nihon U.),
S. Sugita (Nagoya U.), N. Vasquez (Tokyo Tech.),
on behalf of the Suzaku WAM team, report:
The long GRB 090929B (Swift-BAT trigger #371050; Pagani et al., GCN 9963,
Krimm et al. GCN 9979) was detected by the Suzaku Wide-band All-sky
Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at
10:09:23.633 UT (=T0).
The observed light curve shows a multi-peaked structure, starting at
T0-2 s and ending at T0+20 s, with a total duration (T90) of about 18 s.
The fluence in 100 - 1000 keV was (3.92 $B!^(B 0.63) x 10-6 erg/cm2.
The 1-s peak flux measured from T0+1 s was 1.42 (-0.25. +0.24)
photons/cm2/s in the same energy range.
Preliminary result shows that the time-averaged spectrum from
T0-2 s to T0+20 s is well fitted by a single power-law with
a photon index of 1.96 (-0.17, +0.20) (chi2/d.o.f = 23.4/27).
All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.
The light curves for this burst will be available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/untrig/grb_table.html