On the evolutionary status of bright, low-mass X-ray sources

Abstract

view Abstract Citations (312) References (90) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the evolutionary status of bright, low-mass X-ray sources. Webbink, R. F. ; Rappaport, S. ; Savonije, G. J. Abstract A model of bright, low-mass X-ray binaries is proposed which features a lower giant-branch star losing mass on a nuclear time scale to an accreting compact companion. Simple numerical models show that mass transfer rates equal to or greater than 10 to the -9th solar masses per yr are sustained at very nearly a constant rate until the envelope of the donor star is exhausted. The model predicts orbital periods in the range 1-200 days and X-ray to optical luminosity ratios Lx/Lopt = 200-1000 for these sources. It accounts in a natural way for the large fraction of the total galactic bulge luminosity emitted by a few bright (10 to the 37th erg/s or greater) sources. It also accords very well with the observed X-ray and optical properties of the halo source Cyg X-2 and also with those of 2S 0921-63, provided this latter system contains a massive accreting white dwarf rather than a neutron star. Problems of the prior evolution of low-mass X-ray sources are also briefly delineated. Publication: The Astrophysical Journal Pub Date: July 1983 DOI: 10.1086/161159 Bibcode: 1983ApJ...270..678W Keywords: Binary Stars; Giant Stars; Stellar Evolution; Stellar Luminosity; Stellar Mass Accretion; X Ray Sources; Galactic Bulge; Neutron Stars; Stellar Mass Ejection; Stellar Models; White Dwarf Stars; X Ray Binaries; Astrophysics full text sources ADS | data products SIMBAD (4)