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GCN Circular 15014

Subject

GRB 130715A: Suzaku WAM observation of the prompt emission

Date

2013-07-22T08:37:22Z (11 years ago)

From

Makoto Tashiro at Saitama U/Swift <tashiro@phy.saitama-u.ac.jp>

Y. Ishida, M. Tashiro, Y. Terada, T. Yasuda, H. Ueno,
S. Sugimoto (Saitama U.), M. Ohno, K. Takaki, T. Kawano,
R. Nakamura, S. Furui, Y. Fukazawa (Hiroshima 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 long GRB 130715A (Andrew et al GCN15005Not found
 
 
) was detected by the the
Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of
50 keV - 5 MeV at 21:44:38.377 UT (=T0).

The observed light curve shows double-peaked structure starting at
T0-30s, ending at T0+62s with a duration (T90) of about 46 seconds.
The fluence in 100 - 1000 keV was 3.38(+0.31/-0.27)x10^-5 erg/cm^2.
The 1-s peak flux measured from T0s was 2.66(+0.49/-1.36) photons/cm^2/s
in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-30s to
T0+62s is well fitted by a power-law with exponential cutoff model :
   dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
   alpha       1.66(+0.31/-0.65), and
   Epeak       527(+429/-274) keV (chi^2/d.o.f. = 10.2/13).

All the quoted errors are at statistical 90% confidence level, in which
the systematic uncertainties are 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