[vsnet-grb-info 6287] GRB 080523: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7909
SUBJECT: GRB 080523: Suzaku WAM observation of the prompt emission
DATE:    08/06/28 02:39:45 GMT
FROM:    Yoshitaka Hanabata at Hiroshima U  <hanabata at hep01.hepl.hiroshima-u.ac.jp>

Y. Terada, M. Tashiro, Y. Urata, K. Onda, A. Endo, N. Kodaka, K. Morigami, 
T. Sugasahara, W. Iwakiri (Saitama U.),
M. Ohno, M. Kokubun, M. Suzuki, T. Takahashi (ISAS/JAXA),
Y. Fukazawa, T. Takahashi, T. Uehara, C. Kira, Y. Hanabata (Hiroshima U.), 
K. Yamaoka, S. Sugita (Aoyama Gakuin U.),
Y. E. Nakagawa, T. Tamagawa (RIKEN), 
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 080623 (Swift/BAT trigger #315080 ; Ukwatta et al., GCN 7894) 
was detected by the Suzaku Wide-band  All-sky Monitor (WAM) which covers 
an energy range of 50 keV - 5 MeV at 10:25:28 UT on 23 July 2008 (=T0). 
The observed light curve shows a multi-peaked structure starting at T0, 
ending at T0+10 s with a duration (T90) of about 7 seconds. The fluence in 
100 - 1000 keV was (1.6 +/- 0.4) E-6 erg/cm^2. The 1-s peak flux measured 
from T0+ 8 s was 0.5 +/- 0.4 photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0 to T0+10 s
is well fitted by a single power-law with a photon index of 2.0 -0.9+1.0
(chi^2/d.o.f =  5.6 / 8) at the 150 - 600 keV bandpass.
----

All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.

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The light curves with 1-sec time resolution for this burst will be 
appeared at the following URL.
 http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/untrig/grb_table.html