X-ray binaries with neutron stars at different accretion stages
Abstract
Different accretion regimes onto magnetized NSs in HMXBs are considered: wind-fed supersonic (Bondi) regime at high accretion rates ~[g s] , subsonic settling regime at lower and supercritical disc accretion during Roche lobe overflow. In wind-fed stage, NSs in HMXBs reach equilibrium spin periods proportional to binary orbital period . At supercritical accretion stage, the system may appear as a pulsating ULX. Population synthesis of Galactic HMXBs using standard assumptions on the binary evolution and NS formation is presented. Comparison of the model -- (the Corbet diagram), -- and -- distributions with those for the observed HMXBs (including Be X-ray binaries) and pulsating ULXs suggests the importance of the reduction of in non-circular orbits, explaining the location of Be X-ray binaries in the model Corbet diagram, and the universal parameters of pulsating ULXs depending only on the NS magnetic fields.
Keywords
Cite
@article{arxiv.1811.02842,
title = {X-ray binaries with neutron stars at different accretion stages},
author = {Konstantin Postnov and Aleksandre Kuranov and Lev Yungelson},
journal= {arXiv preprint arXiv:1811.02842},
year = {2020}
}
Comments
9 pages, 10 figures, to appear in Proc. IAUS 346