Statistical Research On Radio Pulsars In Globular Clusters Of The Milky Way

The globular cluster is one of the oldest celestial systems in the Milky Way,and their extremely high density of the core is conducive to creating an environment of material exchange between binaries,so forming millisecond pulsars and eclipsing binaries,main sequence star-millisecond pulsar binaries,highly eccentric binaries,etc.Research on these systems have helped to further understand the dynamics of globular clusters,the evolution of binary systems,and interstellar media.Since the discovery of the first radio pulsar in globular cluster M28 in 1987,astronomers have made great progress in the observation and theoretical research of radio pulsars in globular cluster with the continuous construction,use of high sensitivity radio telescopes and the improvement of data digitization processing ability.So far,150 radio pulsars have been observed in 28 globular clusters within 20 kpc of the center of the Milky Way,most of which are millisecond pulsars.It is generally believed that millisecond pulsars are "recycling pulsars" formed by old neutron stars in low-mass X-ray binaries that are re-accelerated by angular momentum from accretion of companion material,globular clusters are the best places to generate and observe millisecond pulsars.Since the 21 st century,astronomers have done some statistical research on the basic properties,search,application and binary system of radio pulsars in globular clusters.With the increasing number of observation samples and the further improvement of relevant parameters,the statistical work of this paper by using the latest sample data of the “The ATNF Pulsar Catalogue”,“Pulsars in Globular Clusters” and “Galaxy Globular Cluster Parameter Table”,and refer to a large number of literature of radio pulsars in globular clusters,on the basis of previous work,it is devoted to updating the research work of the currently known globular cluster radio pulsars and carry out statistical research on related aspects.The main statistical results of this paper on radio pulsars in globular clusters of the Milky Way are as follows:(1)Radio pulsars in globular clusters are mainly millisecond pulsars,and radio pulsars with negative period derivative P are mainly affected by the acceleration effect of gravitational potential in globular clusters.(2)There were far more isolated millisecond pulsars in the cluster than in the extrinsic cluster,and There is currently no uniform explanation for its formation mechanism.(3)Large radio telescopes such as Parkes,Arecibo,GBT,Lovell and GMRT have contributed to the search for globular cluster radio pulsars,among which GBT has observed the largest sample of globular cluster radio pulsars.(4)Most globular clusters with observed radio pulsars are located in the range of-10°~+10° and-4~2kpc from the galactic plane.(5)The companion star types of binary systems in both globular and extrinsic globular clusters are predominantly He white dwarfs.The observed eclipsing binaries include 7 classical Black Widow systems with very low companion mass(Mc<<0.1M?)and 12 Redback systems with non-degenerated companion(Mc~0.2M?).According to the statistics,the wide orbital eclipsing binaries are all Redback systems.Some globular cluster binary systems have observed eclipsing phenomena at different frequencies and even eclipsing delays.The observed eclipsing phenomena indicate that the eclipsing delay is mainly caused by the absorption or scattering of the pulsar's radiation signal when passing through the weak ionizing wind of the companion star.