TITLE: GCN CIRCULAR NUMBER: 10610 SUBJECT: GRB 100414A: Suzaku WAM observation of the prompt emission DATE: 10/04/17 19:42:41 GMT FROM: Kazutaka Yamaoka at Aoyama Gakuin U T. Uehara, Y. Hanabata, T. Takahashi, Y. Fukazawa (Hiroshima U.), K. Yamaoka (Aoyama Gakuin U.), S. Sugita (Nagoya U), Y. Terada, M. Tashiro, S. Hong, A. Endo, K. Onda, T. Sugasahara, W. Iwakiri (Saitama U.), M. Ohno, M. Kokubun, T. Takahashi (ISAS/JAXA), Y. E. Nakagawa, M. Suzuki, T. Tamagawa (RIKEN), N. Ohmori, A. Daikyuji, E. Sonoda, K. Kono, H. Hayashi, K. Noda, Y. Nishioka, M. Yamauchi (Univ. of Miyazaki), N. Vasquez (Tokyo Tech.), Y. Urata, H. M. Lin, P. Tsai (NCU), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), on behalf of the Suzaku WAM team, report: The bright long, Fermi-LAT GRB 100414A (Takahashi et al., GCN 10594; Fermi/GBM trigger #292904423 / 100414097; Foley, GCN 10595) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 02:20:22.879 UT (=T0). The observed light curve shows a multi-peaked structure starting at T0-1.5 s, ending at T0+24.5 s with a duration (T90) of about 22 seconds. The fluence in 100 - 1000 keV was 4.88(-0.36, +0.13)x10-5 erg/cm^2. The 1-s peak flux measured from T0+22.5 s was 6.13(-0.79, +0.40) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-1.5 s to T0+24.5 s is well fitted by a GRB Band model as follows. the low-energy photon index alpha: -0.56(-0.29, +0.37), the high-energy photon index beta: -3.05(-0.53, +0.30), and the peak energy Epeak: 612(-53, +55) keV (chi^2/d.o.f = 34/23). Due to the brightness of this burst, a 3% systematic error was added for low energy channels. In addition, there might be some calibration uncertainties in these spectral parameters because GRB photons came to the WAM detector by passing through the large Ne dewar of the X-ray micro-calorimeter (XRS). All the errors are quoted at 90% confidence level. The light curves for this burst are available at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html