[vsnet-grb-info 12646] GRB 121123A: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14006
SUBJECT: GRB 121123A: Suzaku WAM observation of the prompt emission
DATE:    12/11/27 15:03:15 GMT
FROM:    Makoto Tashiro at Saitama U/Swift  <tashiro at phy.saitama-u.ac.jp>

T.Yasuda, M. Tashiro, Y. Terada, W. Iwakiri, K. Takahara,
M. Asahina, S. Kobayashi, A. Sakamoto, Y. Ishida,
H. Ueno, S. Sugimoto (Saitama U.),
M. Akiyama, N. Ohmori, E. Mochinaga, M. Yamauchi (Univ. of Miyazaki),
K. Yamaoka, Y. E. Nakagawa (Waseda U.),
Y. Hanabata, T. Kawano, K. Takaki, R. Nakamura, Y.Tanaka, M. Ohno,
Y. Fukazawa (Hiroshima U.), S. Sugita (Nagoya U.), M. Kokubun, T.
Takahashi (ISAS/JAXA),
Y. Urata, P. Tsai (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo),
on behalf of the Suzaku WAM team, report:

The long GRB 121123A (Helder et al., GCN 13982; Zhao et al., GCN 13983;
Yurkov et al., GCN 13984; Foley, GCN 13985; Xu et al., GCN 13986;
Guziy et al., GCN 13987; Volnova et al., GCN 13988; Melandri et al.,
GCN 13989; Barthelmy et al., GCN 13990; Evans et al., GCN 13991;
Schmidl et al., GCN 13992) was detected by the the Suzaku Wide-band 
All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV
at 10:06:00 UT (=T0).

The observed light curve shows a single peak followed by a long weak
tail seen up to T0+74 s with a duration (T90) of about 73 seconds.
The fluence in 100 - 1000 keV was 7.72 (+0.44/-7.11) x 10-6 erg/cm^2.
The 1-s peak flux measured from T0+33 s was
0.74 (+0.54/-0.34) photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0+1 s to
T0+74 s is well fitted by a single power-law with a photon index
of 3.29 (+0.64/-0.50) (chi2/d.o.f = 4.7/11).

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