Modelling pulsar glitches with realistic pinning forces: a hydrodynamical approach

TL;DR

This paper models giant pulsar glitches using a two-fluid hydrodynamical approach incorporating realistic pinning forces, successfully reproducing observed glitch behaviors and timings in pulsars like Vela.

Contribution

It introduces a novel hydrodynamical model for pulsar glitches that integrates realistic pinning forces, advancing understanding of glitch mechanisms.

Findings

The model reproduces the glitch rise and relaxation phases.

It matches observed glitch sizes and waiting times.

The approach is consistent with data from multiple pulsars.

Abstract

Although pulsars are one of the most stable clocks in the universe, many of them are observed to 'glitch', i.e. to suddenly increase their spin frequency (\nu) with fractional increases that range from \Delta\nu/\nu \approx 10^{-11} to 10^{-5}. In this paper we focus on the 'giant' glitches, i.e. glitches with fractional increases in the spin rate of the order of \Delta\nu/{\nu} \approx 10^{-6}, that are observed in a sub class of pulsars including the Vela. We show that giant glitches can be modelled with a two-fluid hydrodynamical approach. The model is based on the formalism for superfluid neutron stars of Andersson and Comer (2006) and on the realistic pinning forces of Grill and Pizzochero (2011). We show that all stages of Vela glitches, from the rise to the post-glitch relaxation, can be reproduced with a set of physically reasonable parameters and that the sizes and waiting times between giant glitches in other pulsars are also consistent with our model.