[vsnet-grb-info 12024] GRB 120624B Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13413
SUBJECT: GRB 120624B Suzaku WAM observation of the prompt emission
DATE:    12/07/04 08:26:22 GMT
FROM:    Makoto Tashiro at Saitama U/Swift  <tashiro at phy.saitama-u.ac.jp>

A. Sakamoto, M. Tashiro, Y. Terada, W. Iwakiri, T. Yasuda, K. Takahara,
M. Asahina, S. Kobayashi, H. Ueno (Saitama U.),
M. Akiyama, N. Ohmori,  M. Yamauchi (Univ. of Miyazaki),
K. Yamaoka, Y. E. Nakagawa (Waseda U.),
Y. Hanabata,  T. Kawano, K. Takaki, Y.Tanaka, R. Nakamura, 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 120624B (Fermi/GRM; Gruber et al., GCN 13377,Fermi/LAT;
Vianello et al., GCN 13379,Konus-Wind; Golenetskii et al., GCN
13382,Swift/BAT; Sakamoto et al., GCN 13384)　was detected by the Suzaku
Wide-band  All-sky Monitor (WAM) which covers an energy range of
50 keV - 5 MeV at 22:19:30.985 UT (=T0).

The observed light curve shows  a multi-peaked structure starting at
T0+5 s, ending at T0+279 s, with a duration (T90) of about 274 seconds.
The fluence in　100 - 1000 keV was 1.22(-0.06 +0.02) x 10^-4 erg/cm^2.
The 1-s peak flux measured from T0+274.5s was
6.88(-2.11 +0.27) photons/cm^2/s in the same  energy range.

Preliminary result shows that the time-averaged spectrum from T0-20s to
T0+285s is well fitted by a GRB Band model:
the low-energy photon index alpha: -1.03(-0.16 +0.20),
                      beta        : -2.61 (-0.33, +0.20)
and the peak energy Epeak: 628(-73 +84) keV (chi^2/d.o.f = 72.1/50).

All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.

----
The light curves for this burst will be available at:

http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/untrig/grb_table.html