Modeling of orbital modulation of Cygnus X-3 by particle simulations

TL;DR

This paper uses particle simulations to model the orbital modulation of Cygnus X-3, successfully reproducing observed light curves and spectra by simulating the WR wind and envelope dynamics.

Contribution

It introduces a particle simulation approach to model the circumbinary envelope and orbital modulation of Cygnus X-3, aligning simulated results with observations.

Findings

Simulated light curves match observed IBIS/ISGRI and BATSE data.

Stable envelope formation occurs over a few binary orbits.

Model reproduces observed spectra and radial velocity curves.

Abstract

The formation of the circumbinary envelope of Cygnus X-3 was studied by particle simulations of the WR (Wolf Rayet) companion wind. Light curves resulting from electron scattering absorption in this envelope were computed and compared with observed IBIS/ISGRI and BATSE light curves. The matching was relatively good. For reasonable values of binary parameters (masses, inclination) and wind velocities, a stable envelope was formed during a few binary orbits. Assuming approximately 10^-6 solar mass/year for the rate of the WR-wind, the observed light curves and accretion luminosity can be re-produced (assuming Thomson scattering opacity in the ionized He-rich envelope). The illuminated envelope can also model the CHANDRA-spectrum using the photoionizing XSTAR-code. Furthermore, we discuss observed radial velocity curves of IR emission lines in the context of simulated velocity fields and find good agreement.