The impact of glitches on young pulsar rotational evolution

TL;DR

This study analyzes 124 glitches in 52 young pulsars over a decade, revealing how glitches influence their rotational evolution and providing new insights into their braking indices and glitch properties.

Contribution

It presents the first comprehensive Bayesian analysis of pulsar glitches, measuring their properties and their impact on pulsar spin-down behavior with a large, nearly complete sample.

Findings

Most pulsars exhibit high braking indices (>10) during spin-down episodes.

A near one-to-one relationship exists between inter-glitch braking index and glitch-induced spin-down change.

The glitch sample is complete for fractional spin-frequency increases above approximately 8.1×10^{-9}.

Abstract

We report on a timing programme of 74 young pulsars that have been observed by the Parkes 64-m radio telescope over the past decade. Using modern Bayesian timing techniques, we have measured the properties of 124 glitches in 52 of these pulsars, of which 74 are new. We demonstrate that the glitch sample is complete to fractional increases in spin-frequency greater than $\Delta\nu^{90\%}_{g}/\nu \approx 8.1 \times 10^{-9}$. We measure values of the braking index, $n$, in 33 pulsars. In most of these pulsars, their rotational evolution is dominated by episodes of spin-down with $n > 10$, punctuated by step changes in the spin-down rate at the time of a large glitch. The step changes are such that, averaged over the glitches, the long-term $n$ is small. We find a near one-to-one relationship between the inter-glitch value of $n$ and the change in spin-down of the previous glitch divided by the inter-glitch time interval. We discuss the results in the context of a range of physical models.