[vsnet-grb-info 6436] GRB 080727C: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8050
SUBJECT: GRB 080727C: Suzaku WAM observation of the prompt emission
DATE:    08/08/01 11:12:42 GMT
FROM:    Kazutaka Yamaoka at Aoyama Gakuin U  <yamaoka at phys.aoyama.ac.jp>

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

The long 080727C (Swift/BAT trigger #318170; Parsons et al., GCN 8035)
triggered the Suzaku Wide-band All-sky Monitor (WAM) which
covers an energy range of 50 keV - 5 MeV at 23:07:51.558 UT (=T0).
The observed light curve shows two peaks, starting at T0-13s, ending
at T0+70s, with a duration (T90) of about 54 seconds. The fluence in 150 - 1000 keV 
was (6.0 +/- 0.7) x 10^-6 erg/cm^2. The 1-s peak flux measured from T0+9s was 
0.78 +/- 0.12 photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-7s to T0+47s 
is fitted by a single power-law with a photon index of 1.83 +/- 0.18
in the 150 - 1000 keV range (chi^2/d.o.f = 6.1/11). All the quoted errors are at statistical 
90% confidence level, in which the systematic uncertainties are not included.

The light curves with 1/64 sec time resolution for this burst are now available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html