Magnetic Field Of Ultraluminous X-ray Source NGC 5907U LX-1 And Millisecond Pulsar Birth Rate In The Galaxy

Neutron stars are a class of dense objects in the universe that are of unique importance.Its extreme physical conditions,such as high density,high temperature,high magnetic field,and rapid rotation,can help us better understand the properties of dense stars,and can also be used to test many theories of modern physics.The study of neutron star binaries,such as orbital period,eccentricity and mass of the companion star,can help us to understand the origin and evolution of pulsars.In this paper,we focus on the evolution of neutron stars in binary star systems.We mainly study the evolution distribution of magnetic field and spin period of binary neutron stars,and the formation mechanism and evolution characteristics of millisecond pulsars.The framework of the paper is divided into four parts.Chapter 1 provides a brief introduction to the basic physical properties of neutron stars,including the progress of neutron star discoveries and observations;a brief description of some physical parameters;a brief description of high-mass X-ray binary systems and low-mass X-ray binary systems;and an introduction to the properties of millisecond pulsars,magnetars,and very bright X-ray pulsars.Chapter 2 presents a correlation study of the magnetic field of the third pulsating ultar-luminous X-ray source,NGC 5907 ULX-1.By correlating the accretion torque with the magnetic field,we calculate the present dipole magnetic field of this source,and apply the theory of decay of the pulsar magnetic field due to accretion to study the evolution trend of the magnetic field of NGC 5907 ULX-1 with time and the evolution results.The magnetic field-rotation period distribution of the source is compared with that of pulsar binaries and magnetars,and the possible pulsar classes of NGC 5907 ULX-1 are analyzed.In Chapter 3,based on the formation and evolution process of millisecond pulsars and the orbital period distribution about binary star systems in the Milky Way,we select the kicking velocity of binary star systems,apply the Monte Carlo method to model the birth rate of millisecond pulsars in the Milky Way and the corresponding calculations,and constrain the orbital period distribution of in-river binary star systems in comparison with the results of previous work.The last section summarizes the results obtained from two works,including the investigation of the nature of extremely bright X-ray sources and the formation and accretion evolution of millisecond pulsars.In my future work,I will focus on the correlation between the evolutionary ending of very bright X-ray pulsars and millisecond pulsars,and I will continue to pay attention to the observational progress of very bright X-ray pulsars.