The Effect of Quantized Magnetic Flux Lines on the Dynamics of Superfluid Neutron Star Cores

TL;DR

This paper studies how quantized magnetic flux lines influence the coupling timescales between superfluid components in neutron star cores, revealing that flux tubes significantly accelerate the coupling process.

Contribution

It introduces a detailed analysis of vortex-flux line interactions, including pinning and creep, in neutron star cores, expanding previous models to include various flux configurations.

Findings

Flux tubes reduce coupling timescales significantly.

Toroidal flux arrangements allow creep responses similar to crust superfluid.

Inclusion of flux lines alters dynamical coupling behavior in neutron star cores.

Abstract

We investigate dynamical coupling timescales of a neutron star's superfluid core, taking into account the interactions of quantized neutron vortices with quantized flux lines of the proton superconductor in addition to the previously considered scattering of the charged components against the spontaneous magnetization of the neutron vortex line. We compare the cases where vortex motion is constrained in different ways by the array of magnetic flux tubes associated with superconducting protons. This includes absolute pinning to and creep across a uniform array of flux lines. The effect of a toroidal arrangement of flux lines is also considered. The inclusion of a uniform array of flux tubes in the neutron star core significantly decreases the timescale of coupling between the neutron and proton fluid constituents in all cases. For the toroidal component, creep response similar to that of the inner crust superfluid is possible.