GCN Circular 10224
Subject
GRB 091127: Suzaku WAM observation of the prompt emission
Date
2009-12-01T13:01:32Z (14 years ago)
From
Yusuke Nishioka at Miyazaki U. <yusuke613@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