TITLE: GCN CIRCULAR NUMBER: 14376 SUBJECT: GRB 130408A: Suzaku WAM observation of the prompt emission DATE: 13/04/15 20:47:15 GMT FROM: Masanori Ohno at Hiroshima U K. Takaki, M. Ohno, T. Kawano, R. Nakamura, S. Furui, Y. Fukazawa (Hiroshima U.), M. Tashiro, Y. Terada, T. Yasuda, Y. Ishida, H. Ueno, S. Sugimoto(Saitama U.), K. Yamaoka (Nagoya U.), M. Yamauchi, M. Akiyama, N. Ohmori (Univ. of Miyazaki), S. Sugita (Ehime U.), Y. E. Nakagawa, M. Kokubun, T. Takahashi (ISAS/JAXA), W. Iwakiri(RIKEN), Y. Hanabata (ICRR), Y. Urata (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo) on behalf of the Suzaku WAM team, report: The long GRB 130408A (Lien et al., GCN14361) triggered by the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 21:51:38 UT (=T0). The observed light curve shows a single peak starting at T0-2s, ending at T0+5s with a duration (T90) of about 7 seconds. The fluence in 100 - 1000 keV was 7.18(+0.06/-0.15) x 10^-6 erg/cm^2. The 1-s peak flux measured from T0s was 5.42(+1.37/-2.27) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-2s to T0+5s is well fitted by a single power-law with a photon index of 2.32 (+0.41/-0.34) (chi2/d.o.f = 12.19/13). 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/trig/grb_table.html