On the estimate of the stellar wind velocity of the massive component in OAO 1657-415

Abstract

We discuss manifestations of the accreting neutron star in the massive X-ray binary system OAO 1657-415. We estimate the mass transfer rate between the system components within a scenario of wind-fed accretion and show that the X-ray luminosity of the pulsar can be explained only under condition that the velocity of stellar wind of the massive component in the orbital plane of the system is in the interval 200–500 km/s.