Numerical Modeling of Mass Transfer in Close Binaries

Abstract

The review of gasdynamic models used for the description of the mass exchange in close binaries is presented. Main features of the flow structure are summarized. Special attention is paid to physics of accretion discs in binary systems. It is shown that in self-consistent considerations of gas dynamics of mass transfer in close binaries the interaction of the stream from L1 with the forming accretion disc is shock-free, and, hence, a “hot spot” does not form at the outer edge of the disc. To explain the presence of the observed zones of high luminosity in semidetached binaries a self-consistent “hot line” model is proposed. According to this model the excess energy is released in a shock wave formed due to interaction of the circumdisc halo and the gas stream flowing out of the donor-star through the vicinity of the inner Lagrangian point.