GCN Circular 20082
Subject
Konus-Wind observation of GRB 161017A
Date
2016-10-19T17:42:56Z (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 161017A (Swift-BAT trigger #718023:
Troja et al., GCN 20064, T0(BAT)=17:51:51 UT;
Fermi-GBM observation: Hui & Meegan, GCN 20068;
Lomonosov observation: Sadovnichy et al., GCN 20075)
was detected by Konus-Wind in the waiting mode.
The light curve shows an emission pulse which starts
~10 s before the BAT trigger, peaks at ~T0(BAT)+7 s,
and lasts till ~T0(BAT)+28 s.
The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB161017_T64311/
As observed by Konus-Wind, the burst had a fluence of
(8.5 �� 1.1)x10^-6 erg/cm2 and a 2.944-s peak energy flux,
measured from ~T0(BAT)+7 s, of (8.7 �� 0.2)x10^-7 erg/cm2
(both in the 20 - 10000 keV energy range).
Modeling the KW 3-channel time-integrated spectrum
(from T0(BAT)-10 s to T0(BAT)+28 s) by a power law
with exponential cutoff (CPL) model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.25 �� 0.16, and Ep = 289 �� 73 keV.
Modeling the KW 3-channel spectrum near the peak count rate with
the CPL model yields alpha = -1.17 �� 0.20, and Ep = 404 �� 136 keV.
Assuming the redshift z=2.013 (de Ugarte Postigo et al., GCN 20069)
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 ~8.3x10^52 erg,
the peak luminosity L_iso is ~2.5x10^52 erg/s,
and the rest-frame peak energy of the time-integrated spectrum,
Ep,i, is ~870 keV.
All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.