[vsnet-grb-info 15390] Konus-Wind observation of GRB 140810A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16679
SUBJECT: Konus-Wind observation of GRB 140810A
DATE:    14/08/11 09:25:04 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.Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration GRB 140810A (Fermi-LAT detection: Moretti et al., GCN 16678)
triggered Konus-Wind at T0=67571.433 s UT (18:46:11.433).

The light curve shows a multi-peaked structure with a total duration of ~100 s.
The emission is seen up to 10 MeV.

As observed by Konus-Wind, the burst had a fluence
of 1.5(-0.1,+0.1)x10^-4 erg/cm2, and a 64-ms peak flux,
measured from T0+23.104 s, of 1.3(-0.1,+0.1)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+93.696 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.05 (-0.06,+0.05),
the high energy photon index beta = -2.35 (-0.16,+0.12),
the peak energy Ep = 239 (-26,+25) keV,
chi2 = 105/97 dof.

The spectrum near the peak count rate (measured from T0+16.640 to T0+29.959 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.86 (-0.10,+0.10),
the high energy photon index beta = -2.44 (-0.35,+0.17),
the peak energy Ep = 416 (-47,+63) keV,
chi2 = 87/97 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB140810_T67571/

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