Timing noise and the long-term stability of pulsar profiles

TL;DR

This paper reviews the correlation between pulsar slowdown rates and pulse shape variations, suggesting that magnetospheric state switching causes these phenomena, with implications for pulsar stability and behavior understanding.

Contribution

It extends previous studies to 16 pulsars, demonstrating that magnetospheric state switching explains correlated timing and emission changes in pulsars.

Findings

Correlated slowdown and pulse shape changes observed in 16 pulsars.

Magnetospheric state switching accounts for mode-changing and nulling phenomena.

These phenomena are likely widespread among pulsars.

Abstract

It has recently been shown that there is a close correlation between the slowdown rates and the pulse shapes of six pulsars, and between the slowdown rates and the flux density of three others. This indicates that these phenomena are related by changes in the current flows in the pulsar magnetospheres. In this paper we review the observational status of these studies, which have now been extended to a total of 16 pulsars having correlated slowdown and pulse emission properties. The changes seem to be due to sudden switching between just two discrete magnetospheric states in the well-known processes of mode-changing and pulse nulling. We also address how widespread these phenomena are in the wider pulsar population.