Autocorrelations in pulsar glitch waiting times and sizes

Abstract

ABSTRACT Among the five pulsars with the most recorded rotational glitches, only PSR J0534+2200 is found to have an autocorrelation between consecutive glitch sizes that differs significantly from zero (Spearman correlation coefficient ρ = −0.46, p-value = 0.046). No statistically compelling autocorrelations between consecutive waiting times are found. The autocorrelation observations are interpreted within the framework of a predictive meta-model describing stress release in terms of a state-dependent Poisson process. Specific combinations of size and waiting time autocorrelations are identified, alongside combinations of cross-correlations and size and waiting time distributions, that are allowed or excluded within the meta-model. For example, future observations of any ‘quasi-periodic’ glitching pulsar, such as PSR J0537–6910, should not reveal a positive waiting time autocorrelation. The implications for microphysical models of the stress-release process driving pulsar glitches are discussed briefly.