Nonparametric estimation of the size and waiting time distributions of pulsar glitches

TL;DR

This paper uses nonparametric kernel density estimation to analyze the size and waiting time distributions of pulsar glitches, revealing diverse activity patterns and implications for superfluid vortex models.

Contribution

It introduces a nonparametric approach to estimate glitch distributions and classifies pulsar activity as Poisson-like or quasiperiodic, with robust results across bandwidth choices.

Findings

Two pulsars show decreasing PDFs with Poisson-like activity.

Three pulsars exhibit quasiperiodic activity with broad waiting time dispersion.

No strong evidence for multimodality in the distributions.

Abstract

Glitch size and waiting time probability density functions (PDFs) are estimated for the five pulsars that have glitched most using the nonparametric kernel density estimator. Two objects exhibit decreasing size and waiting time PDFs. Their activity is Poisson-like, and their size statistics are approximately scale-invariant. Three objects exhibit a statistically significant local maximum in the PDFs, including one (PSR J1341$-$6220) which was classified as Poisson-like in previous analyses. Their activity is quasiperiodic, although the dispersion in waiting times is relatively broad. The classification is robust: it is preserved across a wide range of bandwidth choices. There is no compelling evidence for multimodality, but this issue should be revisited when more data become available. The implications for superfluid vortex avalanche models of pulsar glitches are explored briefly.