WIND ACCRETION IN BINARY STARS .1. INTRICACIES OF THE FLOW STRUCTURE

The 3D now structure of wind accretion in a binary system is computed numerically using SPH, taking into account binary rotation as well as wind acceleration. In the adiabatic gamma=1.5 model, high temperatures are reached in a bow shock close to the accreting star. This region could be responsible for the UV emission observed in such systems. In the isothermal model, the bow shock is no longer detached. Moreover, an accretion disc forms around the star. The disc is inclined with respect to the orbital plane and is in differential rotation. The flow structure is considerably more complicated than in the simple plane-parallel picture that is usually employed to describe these systems.