  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.
