[vsnet-grb-info 8723] GRB 091127: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10224
SUBJECT: GRB 091127: Suzaku WAM observation of the prompt emission
DATE:    09/12/01 13:01:32 GMT
FROM:    Yusuke Nishioka at Miyazaki U.  <yusuke613 at astro.miyazaki-u.ac.jp>

 Y. Nishioka, H. Hayashi, N. Ohmori, A. Daikyuji,E. Sonoda, K. Kono,
 K. Noda, M. Yamauchi (Univ. of Miyazaki), T. Sugasahara, M. Tashiro, 
 Y. Terada, A. Endo, K. Onda, W. Iwakiri (Saitama U.), 
 S. Sugita(Nagoya U.), K. Yamaoka (Aoyama  Gakuin U.),
 M. Ohno, M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA),
 Y. E. Nakagawa, T. Tamagawa (RIKEN), N. Ohmori, A. Daikyuji,
 E. Sonoda, K. Kono, H. Hayashi, K. Noda, Y. Nishioka, M. Yamauchi
 (Univ. of Miyazaki), N. Vasquez (Tokyo Tech.), Y. Urata, H.M  Lin (NCU),
 Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.),
 T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Hong
 (Nihon U.), on behalf of the Suzaku WAM team, report

 
 The long GRB 091127 (Swift/BAT trigger #377179 ; Stamatikos et al., 
 GCN 10197; Fermi/GBM trigger #281057147 ; Colleen et al., GCN 10204)  
 triggered the Suzaku Wide-band  All-sky Monitor (WAM) which covers an 
 energy range of 50 keV - 5 MeV at 2009-11-27 23:25:45.155 UT (=T0).


 The observed light curve shows a double-peaked structure starting at T0 s, 
 ending at T0+11 s with a duration (T90) of about 7 seconds. 
 The fluence in 100 - 1000 keV was 7.35 (-0.50, +0.43) x10^-6 erg/cm^2. 
 The 1-s peak flux measured from T0+1 s was 8.94 (-0.70, +0.56) 
 photons/cm^2/s in the same energy range.

 Preliminary result shows that the time-averaged spectrum from T0 s to 
 T0+11 s is well fitted by a single power-law with a photon index of 
 2.33 (-0.12, +0.13) (chi^2/d.o.f = 46.3/34).

 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