[vsnet-grb-info 15203] Konus-Wind observation of GRB 140629A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16495
SUBJECT: Konus-Wind observation of GRB 140629A
DATE:    14/06/30 12:59:28 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 GRB 140629A (Swift-BAT trigger #602884: Lien et al., GCN 16477; 
Cummings et al., GCN 16481; T0(BAT)=14:17:30 UT)
was detected by Konus-Wind in the waiting mode.

The light curve shows a double-peaked structure which started
~4 s before the BAT trigger and lasted till ~T0(BAT)+22 s.

The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB140629A/

As observed by Konus-Wind, the burst had a fluence of
(3.4 ± 0.5)x10^-6 erg/cm2 and a 2.944-s peak energy flux,
measured from ~T0(BAT)+13.450 s, of (4.7 ± 0.7)x10^-7 erg/cm2
(both in the 20 - 10000 keV energy range).

Modeling the KW 3-channel time-integrated spectrum
(from T0(BAT)-4.214 s to T0(BAT)+22.282 s) by a power law
with exponential cutoff (CPL) model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.42 ± 0.54, and Ep = 86 ± 17 keV.

Modelling the 3-channel spectrum near the peak count rate
(from T0(BAT)-13.450 s to T0(BAT)+16.394 s) by
the CPL model yields alpha = -1.50 ± 0.23, and Ep = 156 ± 52 keV.


Assuming the redshift z=2.275 (Moskvitin et al., GCN 16489;
D'Avanzo et al., GCN 16493)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, and Omega_Lambda = 0.73,
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is ~4.4x10^52 erg,
the peak luminosity L_iso is ~2.0x10^52 erg/s,
and the rest-frame peak energy of the time-integrated spectrum,
Ep,i, is ~283 keV.

All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.