The Extended Pulsar Magnetosphere

TL;DR

This paper models the 3D ideal MHD pulsar magnetosphere to a large radius, revealing a stable current sheet, a spiral crossing region with potential instability, and the pulsar antenna radiation pattern, extending previous numerical studies.

Contribution

It extends the numerical modeling of pulsar magnetospheres to ten times the light cylinder radius, revealing detailed structures and potential physical instabilities.

Findings

Stable, smooth current sheet approaching split monopole solution

Spiral crossing region with destabilizing behavior

Presentation of the spiral pulsar antenna radiation pattern

Abstract

We present the structure of the 3D ideal MHD pulsar magnetosphere to a radius ten times that of the light cylinder, a distance about an order of magnitude larger than any previous such numerical treatment. Its overall structure exhibits a stable, smooth, well-defined undulating current sheet which approaches the kinematic split monopole solution of Bogovalov 1999 only after a careful introduction of diffusivity even in the highest resolution simulations. It also exhibits an intriguing spiral region at the crossing of two zero charge surfaces on the current sheet, which shows a destabilizing behavior more prominent in higher resolution simulations. We discuss the possibility that this region is physically (and not numerically) unstable. Finally, we present the spiral pulsar antenna radiation pattern.