The Appearance of a Radio-Pulsar Magnetosphere from a Vacuum with a Strong Magnetic Field. Accumulation of Particles

TL;DR

This paper investigates how electron-positron pairs accumulate in a neutron star's magnetosphere, leading to a dense plasma layer through oscillations, energy losses, and pair creation processes.

Contribution

It demonstrates the formation of a charge-separated plasma layer in the magnetosphere due to particle oscillations and pair creation, a novel insight into pulsar magnetosphere dynamics.

Findings

Particles undergo ultra-relativistic oscillations with frequencies of 10-100 MHz.

Oscillations decay to 1-10 GHz due to radiation losses.

A dense plasma layer forms at the force-free surface, filling the magnetosphere rapidly.

Abstract

The accumulation of electrons and positrons in the vacuum magnetosphere of a neutron star with a surface magnetic field of B~10^12 G is considered. It is shown that particles created in the magnetosphere or falling into the magnetosphere from outside undergo ultra-relativistic oscillations with a frequency of 10-100 MHz. These oscillations decay due to energy losses to curvature radiation and bremsstrahlung, with their frequencies reaching 1-10 GHz. Simultaneously, the particles undergo regular motion along the force-free surface along closed trajectories. This leads to the gradual accumulation of particles at the force-free surface and the formation of a fully charge-separated plasma layer with a density of the order of the Goldreich-Julian density. The presence of a constant source of electron-positron pairs in the magnetosphere due to the absorption of energetic cosmic gamma-rays leads to the growth of this layer, bringing about a rapid filling of the pulsar magnetosphere with electron-positron plasma if the pair-creation multiplication coefficient is sufficiently high.