GCN Circular 20059
Subject
Konus-Wind observation of GRB 161014A
Date
2016-10-16T18:14:06Z (8 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@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 161014A (Swift/BAT observation:
Racusin et al., GCN 20035; Barthelmy et al., GCN 20049;
Fermi GBM observation: Bissaldi, GCN 20051)
triggered Konus-Wind at T0=45088.321 s UT (12:31:28.321).
The light curve shows a multi-peaked pulse with a duration
of ~25 s. A weak, soft pulse is also seen in the burst light
curve around ~T0+95 s, which KW ecliptic latitude response is
consistent with the position of GRB 161014A.
The emission is seen up to ~3 MeV.
As observed by Konus-Wind, the burst had a fluence of
(4.7 �� 0.7)x10^-6 erg/cm2 and a 64-ms peak energy flux,
measured from T0-0.032, of (1.3 �� 0.4)x10^-6 erg/cm2
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+16.640 s)
is best fit in the 20 keV - 5 MeV range by a cutoff power-law
(CPL) function with the following model parameters:
the photon index alpha = -1.15(-0.48,+0.73),
and the peak energy Ep = 226(-79,+267) keV,
chi2 = 92/78 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep with only an upper limit on beta of -1.8,
chi2 = 92/71 dof.
Assuming the redshift z=2.823 (de Ugarte Postigo et al., GCN 20043)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.3, and Omega_Lambda = 0.7,
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is ~8.2x10^52 erg,
the peak luminosity L_iso is ~8.7x10^52 erg/s,
and the rest-frame peak energy of the time-integrated spectrum,
Ep,i, is ~860 keV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB161014_T45088/
All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.