Induced Compression of White Dwarfs by Angular Momentum Loss

TL;DR

This paper studies how isolated white dwarfs with different masses evolve as they lose angular momentum, showing they shrink and become denser over time, with implications for their stability and structure.

Contribution

It provides a detailed analysis of the structural evolution of white dwarfs under angular momentum loss, including stability criteria and timescale effects.

Findings

White dwarfs shrink and increase central density as they lose angular momentum.

All white dwarfs, regardless of mass, tend to become more compact over time.

Structural parameters significantly influence the evolution timescale.

Abstract

We investigate isolated sub- and super-Chandrasekhar white dwarfs which lose angular momentum through magnetic dipole braking. We construct constant rest mass sequences by fulfilling all stability criteria of rotating configurations and show how the main structure of white dwarfs such as the central density, mean radius and angular velocity change with time. We explicitly demonstrate that all isolated white dwarfs regardless of their masses, by angular momentum loss, shrink and increase their central density. We also analyze the effects of the structure parameters on the evolution timescale both in the case of constant magnetic field and constant magnetic flux.