A Study On The Evolution Of Some Peculiar X-Ray Binaries

The formation and evolution theory of X-ray binaries has been developed and improved for a long time.The investigations of X-ray binaries with special observed properties can help us find the deficiencies in the theories,leading to possible breakthroughs.At present,there are some X-ray binaries with properties that cannot be explained by traditional theories,and some of them are hard to identify.Further investigations are needed for a better understanding of the detailed physical mechanisms in their formation and evolution processes.We focus on their peculiar properties and propose to simulate their evolutionary history via star simulation code and to study their birth properties using binary population synthesis code.The first chapter study the rapid orbital expansion in the compact low-mass X-ray binary 2A 1822–371.The neutron star low-mass X-ray binary 2A 1822-371 has an orbital period of 5.57 hr.Mass transfer in such short-period binaries is thought to be driven by magnetic braking with orbital shrinking.However,2A 1822-371 shows a very rapid orbital expansion,implying that mass transfer occurs rapidly in this system.The accretion rate of the NS is observationally estimated to be higher than the Eddington limit,which is also hard to explain by the standard magnetic braking mechanism.In this work,we construct a model to account for the peculiar properties of 2A 1822-371.We assume that the donor star possesses a relatively strong magnetic field,which is coupled with the stellar winds excited by the X-ray radiation from the NS.This would generate efficient angular momentum loss,leading to a high mass transfer rate and hence orbital expansion.We provide possible evolutionary tracks of 2A 1822-371 and study how the input parameters affect the results.The observational implications ofthe irradiation-driven mass loss are also briefly discussed in the context of evolution of low-mass X-ray binaries and millisecond pulsars.In the third chapter,we discuss the neutron star X-ray binaries within supernova remnants.They are very young and rare systems since the lifetime of a SNR is much less than the evolutionary time of X-ray binaries.These systems can provide implications on the early evolution of X-ray binaries.We propose to carry out a population study to investigate these sources.In one hand,population synthesis calculations can provide predictions about the distributions of binary properties and detectability of different kinds of X-ray binaries,giving implications for further observations.In another hand,the population synthesis study may offer some clues about the nature of known sources that are difficult to identify.In the last chapter,we summarize the work introduced and discuss the future works.