Angular Momentum Accretion onto Neutron Stars in Wind-fed Binary Systems

In this study, we investigate accretion processes onto neutron stars (NSs) in High Mass X‐ray Binaries (HMXBs). Especially, we focus on wind‐accretion processes in systems with eccentric orbit. In these systems, accretion wind brings not only mass but also angular momentum. The accreted angular momentum may affect rotational evolution of NS. Hence, we theoretically estimate the transportation efficiency in such wind‐fed HMXB systems. We found that accreted angular momentum is too much, and consequent NS spin will be very fast. It means that we need any breaking mechanisms to explain observed Pspin of NS.