Pulsar glitch recovery and the superfluidity coefficients of bulk nuclear matter

TL;DR

This paper develops a hydrodynamic model of pulsar glitch recovery that explains observed behaviors and allows extraction of nuclear matter properties like shear viscosity and mutual friction from timing data.

Contribution

It introduces a two-component hydrodynamic model linking pulsar glitch recovery to nuclear matter coefficients, validated by fitting high-resolution timing data.

Findings

Model accounts for exponential recovery and overshoot in pulsars

Fitted coefficients align with theoretical predictions for quark matter phases

Provides estimates for shear viscosity, mutual friction, and charged fluid fraction

Abstract

A two-component hydrodynamic model is constructed of the global superfluid flow induced by two-component Ekman pumping during the recovery stage of a glitch. The model successfully accounts for the quasi-exponential recovery observed in pulsars like Vela and the "overshoot" observed in pulsars like the Crab. By fitting the model to high-resolution timing data, three important constitutive coefficients in bulk nuclear matter can be extracted: the shear viscosity, the mutual friction parameter, and the charged fluid fraction. The fitted coefficients for the Crab and Vela are compared with theoretical predictions for several equations of state, including the color-flavor locked and two-flavor color superconductor phases of quark matter.