Global current circuit structure in a resistive pulsar magnetosphere model

TL;DR

This paper develops a resistive pulsar magnetosphere model that incorporates dissipation, revealing how electric resistivity influences current circuits and radiation, thus advancing understanding beyond ideal force-free models.

Contribution

It introduces a self-consistent resistive model with distance-dependent resistivity, expanding the scope of pulsar magnetosphere simulations to include dissipation effects.

Findings

Poloidal current circuits form in the magnetosphere.

Toroidal magnetic-field region expands beyond the light cylinder.

Higher resistivity leads to larger current circuits and increased Poynting flux.

Abstract

Pulsar magnetospheres have strong magnetic fields and large amounts of plasma. The structures of these magnetospheres are studied using force-free electrodynamics. To understand pulsar magnetospheres, discussions must include their outer region. However, force-free electrodynamics is limited in it does not handle dissipation. Therefore, a resistive pulsar magnetic field model is needed. To break the ideal magnetohydrodynamic (MHD) condition $E \cdot B = 0$, Ohm's law is used. In this work, I introduce resistivity depending upon the distance from the star and obtain a self-consistent steady state by time integration. Poloidal current circuits form in the magnetosphere while the toroidal magnetic-field region expands beyond the light cylinder and the Poynting flux radiation appears. High electric resistivity causes a large space scale poloidal current circuit and the magnetosphere radiates a larger Poynting flux than the linear increase outside of the light cylinder radius. The formed poloidal current circuit has width, which grows with the electric conductivity. This result contributes to a more concrete dissipative pulsar magnetosphere model.