T. Enoto, R. Miyawaki, K. Nakawaza, K. Makishima (Univ. of Tokyo),
Y. E. Nakagawa, S. Sugita, K. Yamaoka (Aoyama Gakuin U.),
M. Ohno, T. Takahashi, T. Uehara, C. Kira, Y. Fukazawa (Hiroshima U.),
Y. Urata, K. Onda, M. Suzuki, K. Morigami, N. Kodaka, M. Tashiro (Saitama U.),
M. Suzuki, T. Tamagawa, Y. Terada (RIKEN), S. Hong (Nihon U.),
M. Kokubun, T. Takahashi (ISAS/JAXA), E. Sonoda, M. Yamauchi
(Univ. of Miyazaki), and the Suzaku WAM team report:
The long GRB 070419B (Swift/BAT trigger #276212 ; Parsons et al.,
GCN 6305; Palmer et al., GCN 6327), was detected at 10:44:01 UT (=T0)
by the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy
range of 50 keV - 5 MeV. The observed light curve shows two separate
peak structures with a duration (T90) of about 71 seconds. The fluence
in 100-1000 keV was (1.1 +/-0.2) X 10^-5 erg/cm^2. The 1-s peak flux was
0.9 +/-0.1 photons/cm^2/s in the same energy range.
Preliminary result shows that time-averaged spectrum from T0-5 to
T0+83 sec is well fitted by a single power law with a photon index
of 1.7 +/-0.2.
All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.