[vsnet-grb-info 14034] GRB 131014A: Suzaku WAM observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15348
SUBJECT: GRB 131014A: Suzaku WAM observation of the prompt emission
DATE:    13/10/17 10:20:56 GMT
FROM:    Takafumi Kawano at Hiroshima U/Suzaku-HXD-WAM  <tkawano at hep01.hepl.hiroshima-u.ac.jp>

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



The bright, long GRB 131014A (Fermi GBM detection: Fitzpatrick & Xiong, GCN
15332; Fermi LAT detection: Desiante et al., GCN 15333) triggered the
Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50
keV - 5 MeV at UT 05:09:0.269(=T0).

The observed light curve shows a bright peak followed by a weaker emission
seen up to T0+5 s with a duration (T90) of about 3 seconds.

The fluence in 100 - 1000 keV was 2.02 (-0.11, +0.39) x10^-4 erg/cm^2.

The 1-s peak flux measured from T0+1.6 s was 270 (-28, +34)  photons/cm^2/s
in the same energy range.


Preliminary result shows that the time-averaged spectrum from T0 s to T0+5
s is well fitted by a GRB Band model as follows.

the low-energy photon index alpha: -0.81 (-0.85, +1.16),

the high-energy photon index beta: -2.95 (-0.40, +0.18),

and the peak energy Epeak: 285 (-88, +33) keV, (chi^2/d.o.f = 24.3/23).


All the quoted errors are at statistical 90% confidence level.


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