Formation And Evolution Of Ultraluminous X-ray Pulsar Binaries

Ultraluminous X-ray source(ULXs)is a very important astronomical phenomenon,which has important research significance in the binary evolution,formation of double compact star system and gravitional source.Ultraluminous X–ray sources(ULXs)are defined by apparent(assumed isotropic)luminosities L?10³⁹ergs^-1,which is approximately the Eddington limit for a spherically symmetric accretion onto a stellar mass black hole of 10M_?.Recent observational and theoretical results have suggested that some of ultraluminous X-ray(ULX)sources may contain neutron star(NS)accretors.However,the formation channel and properties of donor stars of NS ULXs remain.How is the ULXs formed?What are its emission mechanism and formation channel?There is no unified conclusion on these issues.In this work,we will study its formation and subsequent evolution of NS Ultraluminous X-ray binaries and contribution to the gravitational wave source.In our work,by adopting the non-conservative and rotation-dependent mass transfer model in the primordial binary evolution,we investigate the way to form pulsar ULXs like observed pulsar ULXs in a systematic way.Our simulation results indicate that pulsar ULXs with Be stars and intermediate or/and high mass donors match observed apparent luminosities,orbital periods and observationally indicated donor masses of known pulsar ULXs.ULXs with Be and intermediate donors are main contributors.The observationally indicated properties of seven known pulsar ULXs can be fully reproduced by the combined results of Be and intermediate mass ULXs.Few known ULXs also can be formed with high mass donors.NS ULXs with He star or low mass donors are not consistent with current observations of seven pulsar ULXs,although they have obvious contributions to NS ULXs in the simulation results.We also study the formation channels of neutron stars.The route of accretion-induced collapse of WDs has 4.5%contribution to the NS ULXs,4.0%of NSs in ULXs are formed through electron-capture supernovae(SNe),and 91.5%of NSs in ULXs are born with core-collapse SNe.We also studied the evolution of pulsar ULXs to double compact star systems.We do not find NS-black hole systems(merging in a Hubble time)that evolved from pulsar ULXs.Pulsar-white dwarf(WD)cases that evolve through pulsar ULXsAbstracthave significant contributions to the whole NS-WD gravitational wave sources.Contributions of pulsar-WD and pulsar-NS cases that experienced pulsar ULXs are?40%and 11%among all LISA NS-WD and NS-NS sources,respectively.Monte Carlo simulation noise with different models give a non-negligible uncertainty.