TITLE: GCN CIRCULAR NUMBER: 10237 SUBJECT: GRB 091126A: Suzaku WAM observation of the prompt emission DATE: 09/12/03 06:12:46 GMT FROM: Hidenori Hayasi at Miyazaki U H. Hayashi, Y.Nishioka, N. Ohmori, A. Daikyuji,E. Sonoda, K. Kono, K. Noda, M. Yamauchi (Univ. of Miyazaki), T. Sugasahara, M. Tashiro, Y. Terada, A. Endo, K. Onda, W. Iwakiri (Saitama U.), S. Sugita(Nagoya U.), K. Yamaoka (Aoyama Gakuin U.), M. Ohno, M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA), Y. E. Nakagawa, T. Tamagawa (RIKEN), N. Vasquez (Tokyo Tech.), Y. Urata, H.M Lin (NCU), Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report The short GRB 091126A (Fermi/GBM trigger #280915166 ; Tierney et al., GCN 10223) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 2009-11-26 07:59:24.67 UT (=T0) The observed light curve shows a single peak starting at T0 , ending at T0+0.5 s with a duration (T90) of about 0.3 seconds. The fluence in 100 - 1000 keV was 5.76 (-1.72,+1.47) x10^-7 erg/cm^2. The 1-s peak flux measured from T0 was 1.57 (-0.84,+0.39) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0 to T0+0.5 s is well fitted by a single power-law with a photon index of 2.27 (-0.43,+0.55) (chi^2/d.o.f. = 20/16). The power-law with exponential cutoff model also gives a good fit with the Epeak of 303(-99,+151) keV, assuming the power-law index of -0.6 as was reported by Tierney et al. (GCN 10223). All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included. 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