TITLE: GCN CIRCULAR NUMBER: 12280 SUBJECT: GRB 110815A : Suzaku WAM observation of the prompt emission DATE: 11/08/19 02:39:31 GMT FROM: Norisuke Ohmori at Miyazaki U N. Ohmori, M. Akiyama, M. Yamauchi (Univ. of Miyazaki), M. Ohno, Y. Hanabata, T. Uehara, T. Takahashi, M. Mizuno, Y. Fukazawa (Hiroshima U.), K. Yamaoka (Aoyama Gakuin U.), S. Sugita (Nagoya U.), T. Yasuda, Y. Terada, W. Iwakiri, K. Takahara, M. Asahina, S. Kobayashi, M. Tashiro (Saitama U.), M. Kokubun, T. Takahashi (ISAS/JAXA), Y. E. Nakagawa (Waseda U.), Y. Urata, P. Tsai, C-J. Chuang (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo), on behalf of the Suzaku WAM team, report: The long GRB110815A (localized by IPN; Hurley et al., GCN12277) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 09:40:57.524 UT (=T0). The observed light curve shows two peaks starting at T0 s, ending at T0+17 s, with a duration (T90) of about 13 seconds. The fluence in 100 - 1000 keV was 2.84 (-0.04, +0.05) x 10^-5 erg/cm^2. The 1-s peak flux measured from T0+2 s was 19.62 (-0.82, +0.92) photons/cm^2/s in the same range. Preliminary result shows that the time-averaged spectrum from T0 s to T0+17 s is well fitted by a power-law with exponential cutoff model: dN/dE ~ E^{-alpha} * exp(-(2-alpha)*E/Epeak) with alpha 1.45 (-0.13, +0.13), and Epeak 300 (-25, +20) keV (chi^2/d.o.f. = 102.1/88). 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