T. Enoto (Univ. of Tokyo), Y.E. Nakagawa, T. Tamagawa (RIKEN),
T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira, Y. Hanabata (Hiroshima
U.), K. Yamaoka, S. Sugita (Aoyama Gakuin U.), M. Tashiro, Y. Terada,
Y. Urata, A. Endo, K. Onda, N. Kodaka, K. Morigami (Saitama U.),
K. Nakazawa, K. Makishima (Univ. of Tokyo), E. Sonoda, M. Yamauchi,
H. Tanaka, R. Hara (Univ. of Miyazaki), M. Ohno, M. Kokubun,
M. Suzuki, T. Takahashi (ISAS/JAXA), S. Hong (Nihon U.),
on behalf of the Suzaku WAM team, report:
The Swift GRB 080413B (Swift/BAT trigger #309111 ; Stamatikos et al., GCN 7598)
was detected by the Suzaku Wide-band All-sky Monitor (WAM) which
covers an energy range of 50 keV - 5 MeV at 8:51:11.645 UT (=T0).
The observed light curve shows a single peak starting at T0-0s,
with a duration (T90) of about 2 seconds. The fluence in 150 - 1000 keV
was (1.4 +/- 0.3) x 10^-6 erg/cm^2. The 1-s peak flux measured from T0+1s was
3.4 +/- 0.2 photons/cm^2/s in the same energy range.
Preliminary result shows that the time-averaged spectrum from T0-1s to T0+8s
is fitted by a single power-law with a photon index of 3.02 (+0.36, -0.32)
(chi^2/d.o.f = 16.7/16) in 150 - 1000 keV. All the quoted errors are at statistical
90% confidence level, in which the systematic uncertainties are not included.
The light curves with 1-sec time resolution for this burst are now available at: