Super-Chandrasekhar White Dwarfs with Magnetic-dependent Equation of State

TL;DR

This paper proposes a magnetic-dependent equation of state for white dwarfs, explaining how ultra-strong magnetic fields can lead to super-Chandrasekhar masses, potentially accounting for over-luminous Type Ia supernovae.

Contribution

It introduces an explicit magnetic-dependent equation of state and analyzes its impact on white dwarf structure, suggesting a mechanism for super-Chandrasekhar white dwarfs.

Findings

Magnetic fields significantly alter white dwarf density profiles.

White dwarf mass can exceed Chandrasekhar limit due to magnetic effects.

Observations of neutron stars and remnants can test the model.

Abstract

Recently, some over-luminous Ia supernovaes are found, suggesting that their progenitors are white dwarfs more massive than the Chandrasekhar limit, which perhaps result from ultra-strong magnetic field inside the white dwarfs. We present an equation of state, explicitly magnetic-dependent and analytically practicable, and observe that the change of equation of states due to magnetic field waning along radium will so significantly influence the configuration of a white dwarf as that its density does not monotonically decrease, but goes down at first, re-peaks near the crust and falls off again. As a supernovae will, in the single degenerate Ia supernovae system, leave the remnant of its companion and a neutron star (pulsar star), we point out that the observations of these objects can put our model into tests