TITLE: GCN CIRCULAR NUMBER: 16457 SUBJECT: GRB 140619B: Suzaku WAM observation of the prompt emission DATE: 14/06/26 02:16:41 GMT FROM: Masanori Ohno at Hiroshima U W. Iwakiri(RIKEN), M. Tashiro, Y. Terada, T. Yasuda, S. Koyama, S. Takeda, T. Nagayoshi, J. Enomoto, S. Nakaya, T. Fujinuma, S. Matsuoka (Saitama U.), M. Yamauchi, N. Ohmori, R. Kinoshita (Univ. of Miyazaki), M. Ohno, T. Kawano, 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 short GRB 140619B (Fermi-GBM detection : Connaughton et al, GCN 16419; Fermi-LAT detection: Kocevski et al., GCN 16420) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 11:24:40.128 UT (=T0). The observed light curve shows a single peak, lasting from T0 to T0+1 s with a duration (T90) of about 0.7 seconds. The fluence in 100 - 1000 keV was 1.50 (+0.07, -0.22) x10^-6 erg/cm^2. The 1-s peak flux measured from T0 was 2.29 (+0.19, -0.53) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0 to T0+1 s is well fitted by a power-law with exponential cutoff model: dN/dE ~ E^{-alpha} * exp(-(2-alpha)*E/Epeak) with alpha 0.45 (+0.31, -0.37), and Epeak 1418 (+292, -239) keV (chi^2/d.o.f. = 23.78/29). 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 will be appeared at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/untrig/grb_table.html