[vsnet-grb-info 6074] GRB 080507: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7708
SUBJECT: GRB 080507: Suzaku WAM observation of the prompt emission
DATE:    08/05/12 03:31:06 GMT
FROM:    Makoto Tashiro at Saitama U/Swift  <tashiro at phy.saitama-u.ac.jp>

T. Sugasahara, K. Onda, M. Tashiro, Y. Terada, Y. Urata, A. Endo,
N. Kodaka, K. Morigami, W. Iwakiri (Saitama U.),
M. Ohno, M. Kokubun, M. Suzuki, T. Takahashi (ISAS/JAXA),
K. Yamaoka, S. Sugita (Aoyama Gakuin U.), Y.E. Nakagawa,
T. Tamagawa (RIKEN), T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira,
Y. Hanabata (Hiroshima U.), T. Enoto, K. Nakazawa,
K. Makishima (Univ. of Tokyo), E. Sonoda, M. Yamauchi, H. Tanaka,
R. Hara (Univ. of Miyazaki), , S. Hong (Nihon U.),
on behalf of the Suzaku WAM team, report:

The long GRB 080507 (SuperAGILE: Lapshov et al., GCN 7697)
triggered the Suzaku Wide-band  All-sky Monitor (WAM) which covers
an energy range of 50 keV - 5 MeV at 07:45:00 UT (=T0). The
observed light curve shows a multi-peaked structure starting at T0,
ending at T0+45s, with a duration (T90) of about 30 seconds.
The fluence in 100 - 1000 keV was 4.1(+0.1,-0.3)*10^-5 erg/cm^2.
The 1-s peak flux measured from T0+2s was 3.5(+0.2,-1.3) photons/cm^2/s
in the same energy range.

A preliminary result shows that the time-averaged spectrum from
T0 to T0+45s is well fitted by a power-law with exponential cutoff model:
   dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
   alpha       0.79(+0.26, -0.28), and
   Epeak       492(+70, -49) keV (chi^2/d.o.f. = 15.9/23).

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