[vsnet-grb-info 15904] GRB 141202A: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17192
SUBJECT: GRB 141202A: Suzaku WAM observation of the prompt emission
DATE:    14/12/19 04:36:16 GMT
FROM:    Makoto Tashiro at Saitama U/Swift  <tashiro at phy.saitama-u.ac.jp>

J. Enomoto, M. Tashiro, Y. Terada, T. Yasuda, S. Koyama, S. Takeda,
S. Nakaya, T. Fujinuma, S. Matsuoka (Saitama U.), M. Yamauchi,
N. Ohmori, R. Kinoshita (Univ. of Miyazaki), W. Iwakiri (RIKEN),
K. Yamaoka (Nagoya U.), S. Sugita (Ehime U.),Y. Hanabata (ICRR),
M. Ohno, T. Kawano, S. Furui, Y. Fukazawa (Hiroshima U.),
Y. E. Nakagawa, M. Kokubun, T. Takahashi (ISAS/JAXA),
Y. Urata (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo)
on behalf of the Suzaku WAM team, report:

The short and IPN localized GRB 141202A (IPN localization: S.
Golenetskii et al., GCN 17131; Fermi GBM Detection: O.J. Roberts et al.,
GCN 17133; Konus-Wind observation: S. Golenetskii et al., GCN 17136)
triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an
energy range of 50 keV - 5 MeV at 11:17:5.508 UT (=T0).

The observed light curve shows a multi-peaked structure lasting from T0s
to T0+2s, followed by a weaker emission seen with a duration (T90) of
about 1.8 seconds. The fluence in 100 - 1000 keV was
4.48 (-0.18, +0.10) x 10^-6 erg/cm^2. The 1-s peak flux measured from
T0+0.5s was 7.61 (-2.44, -0.11) photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0 s to
T0+2 s is well fitted by a power-law with exponential cutoff model:
dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
alpha       0.28 (-0.56, +0.48), and
Epeak       565 (-66, +96) keV (chi^2/d.o.f. = 24.5/25).

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/trig/grb_table.html