TITLE: GCN CIRCULAR NUMBER: 13372 SUBJECT: GRB 120602A: Suzaku WAM observation of the prompt emission DATE: 12/06/20 11:48:02 GMT FROM: Makoto Tashiro at Saitama U/Swift S. Kobayashi, M. Tashiro, Y. Terada, W. Iwakiri, T. Yasuda, K. Takahara, M. Asahina, A. Sakamoto, H. Ueno (Saitama U.), M. Akiyama, N. Ohmori, M. Yamauchi (Univ. of Miyazaki), K. Yamaoka, Y. E. Nakagawa (Waseda U.), Y. Hanabata, T. Kawano, K. Takaki, R. Nakamura, Y.Tanaka, M. Ohno, Y. Fukazawa (Hiroshima U.), S. Sugita (Nagoya U.), M. Kokubun, T. Takahashi (ISAS/JAXA), Y. Urata, P. Tsai (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo), on behalf of the Suzaku WAM team, report: The long GRB 120602A (IPN; Hurley and Goldsten et al., GCN 13365, Konus-Wind; Golenetskii et al., GCN 13366) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 05:00:0.83 UT (=T0). The observed light curve shows a multi-peaked structure starting at T0+5.8 s, ending at T0+59.8 s, with a duration (T90) of about 54 seconds. The fluence in 100 - 1000 keV was 1.97 (-0.03, +0.07) x 10^-4 erg/cm^2. The 1-s peak flux measured from T0+56.4s was 40.0 (+/-1.3) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0s to T0+70s is well fitted by a power-law with exponential cutoff model: dN/dE ~ E^{-alpha} * exp(-(2-alpha)*E/Epeak) with alpha 1.49(-0.13, +0.12), and Epeak 305 (-51, +40) keV (chi^2/d.o.f. = 67.7/48). All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included. ---- The light curves with 1-second time resolution for this burst are available at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/untrig/grb_table.html