TITLE: GCN CIRCULAR NUMBER: 6931 SUBJECT: GRB 071010B: Suzaku WAM observation of the prompt emission DATE: 07/10/18 02:57:14 GMT FROM: Masanori Ohno at Hiroshima U C. Kira, M. Ohno, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.), Y. Terada, T. Tamagawa (RIKEN), K. Yamaoka, Y. E. Nakagawa, S. Sugita (Aoyama Gakuin U.), M. Tashiro, Y. Urata, A. Endo, K. Onda, M. Suzuki, N. Kodaka, K. Morigami (Saitama U.), T. Enoto, R. Miyawaki, K. Nakazawa, K. Makishima (Univ. of Tokyo), E. Sonoda, M.Yamauchi, S. Maeno, H. Tanaka, R. Hara (Univ. of Miyazaki), M. Kokubun, M. Suzuki, T. Takahashi (ISAS/JAXA), S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report: The long GRB 071010B (Swift/BAT trigger #293795; C. B. Markwardt et al., GCN 6871, 6877) was triggered by the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 2007-10-10 20:45:49 UT (=T0). The observed light curve shows a single FRED-like peak, starting at T0-3s, ending at T0+10s, with a duration (T90) of about 5 seconds. There is no signal corresponding to the pre-trigger pulse and the weak soft tail detected by the Swift/BAT (GCN Report 92.1) and the Konus-Wind (GCN 6879) in the WAM energy band (50-5000 keV). The fluence in 100 - 1000 keV was (1.8 +/- 0.3)*10^-6 erg/cm^2. The 1-s peak flux measured from T0+1s was 1.1 +/- 0.3 photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-3s to T0+10s is well fitted by a single power-law with a photon index of 3.2 (-0.5, +0.7) (chi^2/d.o.f = 6/8 ). 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