The influence of radiation pressure on equipotential surfaces in high-temperature binary systems

Abstract

In this paper we considered the effect of the radiation pressure from both components of the high-temperature binary systems in terms of a modified Roche potential. Usually, the parameters of radiation pressures δ1, δ2 can be written as a function of radiiR, effective temperatureT eff , and massM of components. The simulation calculation shows that the positions of saddle pointsL 1 ,L 2 ,L 3 and shape of critical surface are changed with radiation pressure factors δ1, δ2. Consequently, use of the conventional critical Roche model to estimate value of radii and mass ratios may be completely unwarranted if effective temperature of both componentsT eff ≥30 000 K. These conclusions are applied to Wolf-Rayet binary systems V444 Cygni,v 2 Velorum, and O-type binary system Y Cygni. The modified critical potentials are calculated and discussed.