Faculty of Engineering, Hokkai-Gakuen University, Toyohira-ku, Sapporo 062-8605, Japan

摘要

2D modeling of gas flow structure in a binary system using the modified model on a fine grid has been carried out for the parameters of the classical symbiotic star Z And. The calculations have confirmed the mechanism of quiescent to active state change as a consequence of the transition from the disk accretion to the accretion from the flow proposed in our previous works. The simulations of the flow structure for the active state of the system have been also carried out. The thermonuclear runaway on the accretor has been modeled by the pressure jump on the accretor's surface. It has been shown that the introduction of the pressure jump leads to the formation of the structure of two shocks and the contact discontinuity in the space between components of the system. The modeled changes of parameters caused by the formation of these shocks are found to be in agreement with the observed brightness changes.