[vsnet-grb-info 15336] Konus-Wind observation of GRB 140723A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16628
SUBJECT: Konus-Wind observation of GRB 140723A
DATE:    14/07/24 11:27:45 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred at mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lyssenko, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration, hard-spectrum GRB 140723A
(Fermi-LAT detection: Bissaldi et al., GCN 16623;
IPN triangulation: Hurley et al., GCN 16625;
Fermi-BBM detection: Burns, GCN 16626)
triggered Konus-Wind at T0=5790.357 s UT (01:36:30.357).

The light curve shows a single FRED-like pulse
with a total duration of ~45 s.
The emission is seen up to 10 MeV.

As observed by Konus-Wind, the burst had a fluence
of 2.3(-0.5,+0.8)x10^-5 erg/cm2, and a 64-ms peak flux,
measured from T0-0.064 s, of 5.8(-1.6,+1.9)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+33.024 s)
is best fit in the 20 keV - 15 MeV range
by the cutoff power law with the following model parameters:
the photon index alpha = -1.10(-0.20,+0.26),
and the peak energy Ep = 1142(-452,+1005) keV,
chi2 = 71/98 dof.
Fitting this spectrum with the Band model yields the same
values of alpha and Ep with an upper limit on beta of -1.9

The spectrum near the peak count rate (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range
by the cutoff power law with the following model parameters:
the photon index alpha = -1.03(-0.21,+0.26),
and the peak energy Ep = 931(-287,+528) keV,
chi2 = 97/98 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB140723_T05790/

All the quoted errors are at the 90% sigma confidence level.
All the quoted values are preliminary.