Study On High Energy Radiation Process In Pulsar Magnetosphere

Pulsars are an important source of the gamma rays of the Milky Way.Over the years,they have accumulated abundant observation data,and theoretical research has also made outstanding progress.However,the current mechanism of pulsar high-energy radiation is not yet clear.Among them,the problems of the gamma ray radiation mechanism,the position of the particle acceleration region and its detailed structure need to be solved urgently.Based on the analysis of the observation data of Fermi Gamma-Ray Space Telescope,we found that the pulsar’s radiation profile and gammaray energy spectrum have obvious evolution phenomena with the changes of photon energy and rotation phase.The difference in the radiation process.Therefore,based on the outer-gap radiation model,this paper studies the structure and properties of the acceleration region in the pulsar magnetosphere in detail,and improves the existing theoretical model:(1)Recalculated the radius of curvature of the local magnetic field by numerical methods;(2)By solving the radial electrodynamic equations in the gap,considering the influence of the radiation process in the gap on the acceleration field,the radial distribution of the acceleration electric field and the energy distribution of the accelerated particles are self-consistently given.We calculated the energy spectrum and energy-dependent light curve of PSRJ0007 + 7303 in detail with the constructed model.Our theoretical model can better produce the observed characteristics of the pulsar,and the calculation result shows:(1)The energy spectrum of the pulsar can be generated by the curvature radiation process of accelerated electrons in the gap.Due to the distribution of the acceleration electric field in the gap,the characteristic energy of the curvature radiation at different positions varies significantly with the phase;(2)For PSRJ0007 + 7303,the multi-band radiation profile can be generated by a single magnetic pole,and there are obvious differences in the radiation profiles of different bands.This characteristic can be caused by the radial distribution of the radiation position of each phase in the gap and the change of the radius of curvature of the local magnetic field.