TITLE: GCN CIRCULAR NUMBER: 16039 SUBJECT: GRB 140323A : Suzaku WAM observation of the prompt emission DATE: 14/03/27 07:53:42 GMT FROM: Tetsuya Yasuda at Saitama U W. Iwakiri(RIKEN), M. Tashiro, Y. Terada, T. Yasuda, Y. Ishida, H. Ueno, S. Sugimoto, S. Koyama, S. Takeda, T. Nagayoshi (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. Hanabata (ICRR), Y. E. Nakagawa, M. Kokubun, T. Takahashi (ISAS/JAXA), Y. Urata (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo) on behalf of the Suzaku WAM team, report: The long GRB 140323A (Swift/BAT trigger #592916 ; Troja et al., GCN 16027; Sakamoto et al., GCN 16029; Fermi-GBM detection : Yu and von Kienlin, GCN 16032; Fermi-LAT detection: Vianello et al., GCN 16034; Konus-Wind detection : Golenetskii et al., GCN16035) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 10:23:12.262 UT (=T0). The observed light curve shows a multi-peaked structure in two main episodes lasting from T0-15 s to T0+95 s with a duration (T90) of about 90 seconds. The fluence in 100 - 1000 keV was 1.36 (+/- 0.12) x10^-6 erg/cm^2. The 1-s peak flux measured from T0+6 s was 2.17 (+0.35, -0.45) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-10 s to T0+95 s is well fitted in 200 keV to 5 MeV by a single power-law with a photon index of 2.64 (+0.34, -0.28) (chi^2/d.o.f = 12.5/14). 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