Supernovae and the Evolution of Close Binary Systems

Abstract

The presence of neutron stars and black holes in X-ray binaries, as companions to normal stars, implies that core-collapse supernovae do occur in binary systems and that these systems can survive as binaries after the explosions. The main part of this chapter is devoted to the formation and evolution of X-ray binaries and their descendants: double compact objects such as binary radio pulsars and double black holes. It is shown that large-scale mass transfer is crucial for understanding the formation of high-mass X-ray binaries (HMXBs) and that these systems represent a normal stage in the evolution of massive binary systems. On the other hand, low-mass X-ray binaries (LMXBs) are products of a rare type of binary evolution, and very special conditions are required for the systems to have survived binary evolution and the supernova explosion. Later evolution of HMXBs may lead to double neutron stars, double black holes, or black hole-neutron star binaries; most LMXBs will produce millisecond radio pulsars with white dwarf companions. A second type of supernovae that is exclusively related to binaries are the thermonuclear supernovae, which are produced by the thermonuclear explosion of a carbon-oxygen white dwarf, of which the mass has grown to reach the upper mass limit allowed for a white dwarf (Chandrasekhar limit). These so-called type Ia supernovae are "standard candles," crucial for cosmology. They can only be produced in binary systems, as the only realistic way to make the mass of a white dwarf grow is by mass transfer in a binary system.