TITLE: GCN CIRCULAR NUMBER: 7551 SUBJECT: GRB 080328: Suzaku WAM observation of the prompt emission DATE: 08/03/30 23:10:38 GMT FROM: Makoto Tashiro at Saitama U/Swift N. Kodaka, M. Tashiro, Y. Terada, Y. Urata, A. Endo, K. Onda, M. Suzuki, K. Morigami (Saitama U.), K. Yamaoka, Y. E. Nakagawa, S. Sugita (Aoyama Gakuin U.), M. Ohno, T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira, Y. Hanabata (Hiroshima U.), T. Tamagawa (RIKEN), T. Enoto, R. Miyawaki, K. Nakazawa, K. Makishima (Univ. of Tokyo), E. Sonoda, M. Yamauchi, 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 080328 (Swift/BAT trigger #307931 ; Perri et al., GCN 7525) was detected by the the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 2008-03-28 08:03:14 UT (=T0). The observed light curve shows a multi-peaked structure starting at T0+0s, ending at T0+100 with a duration (T90) of about 85 seconds. The fluence in 100 - 1000 keV was 1.61 (-0.40,+0.37) * 10^-5 erg/cm^2. The 1-s peak flux measured from T0+0s was 6.4 (-0.39,+0.39) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-0s to T0+100s is well fitted by a single power-law with a photon index of 1.72 (-0.26, +0.38) (chi^2/d.o.f = 11.9/15). 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