[vsnet-grb-info 18187] Konus-Wind observation of GRB 160629A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19635
SUBJECT: Konus-Wind observation of GRB 160629A
DATE:    16/06/30 18:37:43 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred at mail.ioffe.ru>

D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 160629A (INTEGRAL detection: Gotz et al., GCN 19621;
Fermi GBM observation: Toelge, GCN 19628)
triggered Konus-Wind at T0=80385.314 s UT (22:19:45.314).

The light curve shows a smooth pulse with a total duration of ~40 s.
The weaker subsequent emission is traceable up to ~T0+70 s.
The emission in the main pulse is seen up to ~4 MeV.

As observed by Konus-Wind, the burst had a fluence
of 1.5(-0.4,+0.6)x10^-5 erg/cm2, and a 64-ms peak flux,
measured from T0+10.560 s, of 1.4(-0.3,+0.3)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+24.832 s)
is best fit in the 20 keV - 5 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.79 (-0.17,+0.23),
the high energy photon index beta = -2.92 (-3.68,+0.50),
the peak energy Ep = 227 (-41,+41) keV,
chi2 = 76/76 dof.

Assuming the redshift z=3.332 (Castro-Tirado et al., GCN Circ. 19632)
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 ~3.7x10^53 erg,
the peak luminosity L_iso is ~1.5x10^53 erg/s,
and the rest-frame peak energy of the time-integrated spectrum,
Ep,i, is ~980 keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160629_T80385/

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