General Relativistic White Dwarfs and Their Astrophysical Implications

TL;DR

This paper explores the properties and astrophysical implications of general relativistic, rapidly-rotating white dwarfs, including their role in supernovae, magnetars, and related phenomena, with estimates of their physical parameters.

Contribution

It introduces models of stable, rotating white dwarfs in general relativity and applies them to explain phenomena like supernovae and magnetars, providing bounds on their physical properties.

Findings

Estimated spin-down lifetimes due to magnetic braking.

Boundaries for mass, radius, and magnetic field of white dwarfs.

Proposed white dwarf models for Soft Gamma Repeaters and Magnetars.

Abstract

We consider applications of general relativistic uniformly-rotating white dwarfs to several astrophysical phenomena related to the spin-up and the spin-down epochs and to delayed type Ia supernova explosions of super-Chandrasekhar white dwarfs, where we estimate the "spinning down" lifetime due to magnetic-dipole braking. In addition, we describe the physical properties of Soft Gamma Repeaters and Anomalous X-Ray Pulsars as massive rapidly-rotating highly-magnetized white dwarfs. Particularly we consider one of the so-called low-magnetic-field magnetars SGR 0418+5729 as a massive rapidly-rotating highly-magnetized white dwarf and give bounds for the mass, radius, moment of inertia, and magnetic field by requiring the general relativistic uniformly-rotating configurations to be stable.