A Particle Simulation for the Pulsar Magnetosphere: Relationship of Polar Cap, Slot Gap, and Outer Gap

TL;DR

This paper presents a particle simulation of pulsar magnetospheres, revealing a new global structure with a current-neutral zone that unifies the polar cap, slot gap, and outer gap models, advancing understanding of pulsar emission regions.

Contribution

It introduces a novel global magnetospheric structure with a current-neutral zone, clarifying the spatial relationship among different emission models in pulsars.

Findings

Discovery of a current-neutral zone along the boundary of oppositely directed currents.

Identification of the locations of polar cap, slot gap, and outer gap regions relative to the current-neutral zone.

Estimation of the super-rotation region in the pulsar magnetosphere.

Abstract

To explain the pulsed emission of the rotation powered pulsars from radio to gamma-ray, the polar cap models, the slot gap models, and the outer gap models are proposed. The recent observations suggest that these models are likely to co-exist in the same magnetosphere. If so, their mutual relation is known to be troublesome (Harding 2009) due to the boundary conditions and the direction of the current which are properly assumed in each acceleration models. We performed a particle simulation for the global magnetospheric structure. Based on the simulation, we present a new picture of the global structure of the pulsar magnetosphere. It is found that a new dead zone is formed along the current neutral line which separates the oppositely directed current. We shall call this the current- neutral zone. We suggest that the polar cap accelerators and the slot gaps locate above the current-neutral zone, and the outer gap exist between the current neutral zone and the traditional dead zone. We also give an estimate of the super-rotation region.