Oscillating wind accretion due to X-ray inhibition of line-driven mechanism

Abstract In a high-mass X-ray binary system with a massive donor, the line-driven stellar wind accretes on to a compact object, emitting X-rays in the process. Ionizing the stellar wind matter using X-rays inhibits its acceleration, leading to changes in wind velocity due to X-ray irradiation from the compact accretor. Since the stellar wind velocity influences mass accretion rate and subsequent X-ray luminosity, the inhibiting effect of X-ray ionization on wind acceleration could potentially impact the mass accretion process. This study investigates the correlation between the accretion rate on a compact object and the acceleration process of stellar wind matter by using a simple model. Results indicate that the mass accretion rate exhibits spontaneous oscillations, causing quasiperiodic flares when considering the ionization of wind matter. Such a feedback process of X-ray ionization on the mass accretion rate could be related to the mechanism of flare production in X-ray binaries.