Stellar Evolution and the Formation of Neutron Stars in Binary Systems

Abstract

The evolution of single stars is reviewed and the possible types of remnants are discussed. Subsequently, mechanisms for the formation of neutron stars in binary systems are reviewed. In close binary systems, stars in the (zero-age) mass range from about 10 to over 40 solar masses are expected to leave neutron stars as remnants. In wide binaries and for single stars the lower limit is reduced to about 8 solar masses. The precise value of the lower limit depends on various input parameters, especially on the treatment of convection. Accretion-induced collapse (AIC) of a white dwarf of suitable mass and chemical composition is a second viable mechanism for the formation of neutron stars in binary systems. Evidence is summarized indicating that both in the wide radio pulsar binaries and in the bright galactic bulge X-ray sources that exhibit quasi-periodic oscillations the neutron stars were formed by AIC.