The Simulation Of Magnetosphere And High Energy Radiation Of The Pulsars

In the study of high energy radiation of the pulsars,since the questions on the realistic magnetospheres of pulsars,the position of the production of the high energy radiation,and the acceleration and radiation of particles within the magnetospheres,are still uncertain,thus they are always an important topic in the study of physics of the pulsars.In that sense,based on the detailed simulations of the three dimensional magnetospheres of the pulsars,the characteristics of the high energy radiation from the magnetospheres are further inves tigated in this thesis.We start with numerically simulating the time-dependent Maxwell equations to construct the realistic dissipative magnetosphere with the emergence of the dissipative regions self-consistently.This kind of magnetosphere structures and dissipative regions are constrained by the conductivity:when the conductivity approaches the value of infinity,the magnetosphere will approximate the force-free configuration and the dissipative regions will gradually contract;while the conductivity approaches zero,the magnetosphere will come back to the vacuum state.Moreover,to better capture the current sheet structures at which the accelerating electric fields locate,we enforce an extra constraint that the electric field should less than or equate with the magnetic field.In this dissipative magnetosphere,we firstly study from the uniform radiation scenario the energy-independent high energy radiation characteristics of the pulsars by using the geometric method,and place the dissipative regions at the areas of the magnetospheres within the light cylinder radius.Then we also study the energy-independent high energy radiation characteristics by using the particle trajectory method.We inject millions of particles from the polar cap of the pulsar randomly,considering also the influences of the acceleration of the accelerating electric field in the dissipative regions and the curvature loss on the particles;during the the motion of the particles we compute the Lorentz factors of the particles being accelerated at arbitrary positions along their trajectories,and collect at the same time the bolometric luminosity of curvature radiation to study the energy-independent high energy radiation characteristics.These two methods are used to study the Vela pulsar:the results show that,in the geometric model,the low value of conductivity is favorable for the observed pattern,on the contrary,the high value of conductivity is favorable for the observed pattern in the particle trajectory method.Moreover,we use the model of Force-free Inside and Dissipative Outside(FIDO)magnetosphere to expand the previous study by computing directly the spectrum of every particle.The FIDO models are applied to two specific pulsars,Crab and Vela,in order to study the characteristics of the high energy radiations from the magnetospheres of the pulsars.However,we cannot precisely assert that the positions of the production of the high energy radiation of the pulsars originate either from the magnetospheres within the light cylinder or from the equatorial current sheet outside the light cylinder.Finally,taking into account the radiation-reaction of the high energy radiation photons onto the motion of the particles,we use the Aristotelian Electrodynamics(AE)and present the structures of the three dimensional AE magnetospheres and the distribution patterns of the dissipative regions in the magnetospheres by using the spectral method.The results show that increasing the multiplicity the AE magnetospheres will approach the force-free structure and the dissipative regions will be restrained in the equatorial current sheet outside light cylinder;while for the lower multiplicity the equatorial current sheet outside the light cylinder possess much wider dissipative regions and the AE magnetospheres are still similar to the force-free ones but not return to the vacuum ones.