The Wind Braking Model Of Pulsars Under The Ring Acceleration Gap

Pulsar is a fast rotating neutron star with a strong magnetic field.Every revolution will produce a radiation pulse.Its radiation range covers all electromagnetic bands from radio to ?-ray.Although pulsars have been discovered as early as 1960 s,the radiation mechanism of pulsars is still a mystery.It is generally believed that the radiation of pulsar comes from its rotational energy,this means that the change of pulsar's radiation will be accompanied by the change of pulsar's rotation.And some relations between the rotation of pulsar and its radiation have been found in the actual observation,such as the spin down rate and radiation intensity changing at the same time.Therefore,we can take this as a starting point to explore the radiation mechanism of pulsar by studying the rotation and braking of pulsar.In the wind braking model,the charged particles in the magnetosphere of pulsar will radiate and take part of the rotational energy away during the process of outflow and acceleration,which will affect the rotation of pulsar.So the wind model can naturally explain the rotation of pulsars and the correlation between rotation and radiation.Previous researchers have used the wind braking model to explain the periodic higher spin down rate of the intermittent pulsar in the radio on state than radio off state,and simulate the rotation evolution of general pulsar.The wind model depends on the acceleration gap in the magnetosphere.Previous work mainly used a certain acceleration gap or the coexistence of two acceleration gaps,such as vacuum gap.But there are many kinds of accelerating gaps in the real pulsar magnetosphere,such as vacuum gap,outer gap,annular gap,slot gap and so on.Therefore,for the pulsar braking,the acceleration gap above is likely to participate in the pulsar braking.In this paper,different from previous studies,wind braking model in the annular acceleration gap considering both core and annular region with different acceleration potential was established,which is used to explain the observations of intermittent pulsar and Crab pulsar.The calculation results show that the annular acceleration gap can also be applied to the wind braking model compared with the vacuum acceleration gap and the outer acceleration gap and so on.In addition,along with the increase of the rotation velocity of pulsar,the acceleration effect of the annular acceleration gap will increase sharply compared with that of the vacuum acceleration gap.On the one hand,the results of this paper enrich the wind braking model,on the other hand,because the radiation of pulsar is generated in the acceleration gap.This indicates that for the high-energy radiation of pulsar(such as Crab pulsar),such as X-ray,?-ray may be generated in the annular gap region of pulsar magnetosphere,which will provides reference value for observation.