[vsnet-grb-info 3893] GRB 061007: Suzaku/WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  5724
SUBJECT: GRB 061007: Suzaku/WAM observation of the prompt emission
DATE:    06/10/09 15:44:20 GMT
FROM:    Kazutaka Yamaoka at Aoyama Gakuin U  <yamaoka at phys.aoyama.ac.jp>

 K. Yamaoka, S. Sugita (Aoyama Gakuin U.), M. Ohno, T. Takahashi, 
 T. Asano, T. Uehara, Y. Fukazawa (Hiroshima U.), Y. Terada, M. Suzuki, 
 T. Tamagawa (RIKEN), M. Tashiro, K. Abe, K. Onda, Y. Sato, M. Suzuki, 
 Y. Urata (Saitama U.), T. Enoto, R. Miyawaki, K. Kokubun, K. Makishima 
 (Univ. of Tokyo), K. Nakazawa, T. Takahashi (ISAS/JAXA), S. Hong (Nihon U.), 
 on behalf of the Suzaku WAM team report:

 The bright, long burst, GRB 061007 (Schady et al., GCN 5707; Markwardt 
 et al., GCN 5713),  triggered the Suzaku Wide-band All-sky Monitor (WAM), 
 which covers the energy range of 50 keV - 5 MeV, at 10:08:05.627 (UT).
 Three large peaks as well as a following smaller peak (GCN 5713) were 
 clearly seen in the WAM light curve. The T90 duration was about 59 seconds.
 The fluence in 100 - 1000 keV was 1.38x10-4 erg/cm2, while the 1-s peak 
 flux was 14.3 (-1.0,+0.3) photons/cm2/s in the same energy range.

 Preliminary result shows that the time-averaged spectrum is 
 well-described with a GRB Band model as follows.

  the low-energy photon index alpha: -0.68 +- 0.11, 
  the high-energy photon index beta: -2.87 (-0.60, +0.28), 
  the break energy E0:       425 (-51, +58) keV,
  and the peak energy Epeak: 561 (-27, +29) keV.
  
 All the quoted errors are at statistical 90% confidence level,
 while systematic errors are not included.

 The WAM light curve of this event is available at 
 http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/grb_table.html