Pulsar glitch activities: the spin parameters approach

TL;DR

This paper investigates the relationship between pulsar glitch activity and spin parameters, proposing a quadratic model that improves estimates of glitch activity for pulsars with limited observational data.

Contribution

It introduces a quadratic fitting method to better estimate pulsar glitch activity parameters from spin data, extending analysis to pulsars lacking direct glitch observations.

Findings

Quadratic functions better fit the relationship between activity parameters and spin parameters.

Estimated activity parameters align with observed data across pulsar populations.

Method enables activity estimation for pulsars without recorded glitches.

Abstract

Glitch activity refers to the mean increase in pulsar spin frequency per year due to rotational glitches. It is an important tool for studying super-nuclear matter using neutron star interiors as templates. Glitch events are typically observed in the spin frequency ($\nu$) and frequency derivative ($\dot{\nu}$) of pulsars. The rate of glitch recurrence decreases as the pulsar ages, and the activity parameter is usually measured by linear regression of cumulative glitches over a given period. This method is effective for pulsars with multiple regular glitch events. However, due to the scarcity of glitch events and the difficulty of monitoring all known pulsars, only a few have multiple records of glitch events. This limits the use of the activity parameter in studying neutron star interiors with multiple pulsars. In this study, we examined the relationship between the activity parameters and pulsar spin parameters (spin frequency, frequency derivative, and pulsar characteristic age). We found that a quadratic function provides a better fit for the relationship between activity parameters and spin parameters than the commonly used linear functions. Using this information, we were able to estimate the activity parameters of other pulsars that do not have records of glitches. Our analysis shows that the relationship between the estimated activity parameters and pulsar spin parameters is consistent with that of the observed activity parameters in the ensemble of pulsars.