Radiative disk winds in supersoft X-ray sources

Since they depend on inclination angles, P Cyg profiles observed in CVs strongly suggest the existence of accretion disk winds in CVs. Recently, X-ray observations revealed bipolar outflows in SSXSs. The wind velocity measured in these observations is about 3000-5000 km s(-1), which is of the order of the escape velocity of white dwarfs. Hence, it is supposed that the winds originate from the inner disk and/or the boundary layers between the disk and white dwarf. We examined radiatively-accelerated accretion-disk winds, and found that the terminal speed of the wind emanating from the inner disk becomes similar to 0.6 root GM/R*, where M is the white dwarf mass and R* the inner radius of the disk (= the white dwarf radius).