TITLE: GCN CIRCULAR NUMBER: 15984 SUBJECT: GRB140308A: Suzaku WAM observation of the prompt emission DATE: 14/03/15 08:46:38 GMT FROM: Makoto Tashiro at Saitama U/Swift T. Nagayoshi, M. Tashiro, Y. Terada, S. Koyama, T. Yasuda, S. Takeda, Y.���Ishida, H. Ueno, S. Sugimoto (Saitama U.), M. Yamauchi, N. Ohmori, M. Akiyama, R. Kinoshita (Univ. of Miyazaki), M. Ohno, K. Takaki, T. Kawano, R. Nakamura, S. Furui,���Y. Fukazawa (Hiroshima U.), K. Yamaoka (Nagoya U.), 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 140308A (Konus-Wind detection: S. Golenetskii et al., GCN 15943, IPN localization: S. Golenetskii et al., GCN 15941) was triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 03:49:26.030 UT (=T0). The observed light curve shows a multi-peaked structure starting at T0-10 s, ending at T0+80 s with a duration (T90) of about 64 seconds. The fluence in 100 - 1000 keV was 4.02 (-0.78, +0.14) x10^-5 erg/cm^2. The 1-s peak flux measured from T0+20 s was 7.71 (-5.71, +0.07) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-10 s to T0+80 s is well fitted by a GRB Band model in 90 keV to 5 MeV. the low-energy photon index alpha: -0.95 (-0.44, +1.11), the high-energy photon index beta: -2.20 (-0.23, +0.14), and the peak energy Epeak: 386 (-128, +132) keV (chi^2/d.o.f = 24.9/25). Due to the brightness of this burst, a 3% systematic error was added for low energy channels. All the quoted errors are at statistical 90% confidence level. 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