Effect of field dissipation and cooling on the mass-radius relation of strongly magnetised white dwarfs

Understand

We investigate the luminosity suppression and its effect on the mass-radius relation as well as cooling evolution of highly magnetised white dwarfs.

• Based on the effect of magnetic field relative to gravitational energy, we suitably modify our treatment of the radiative opacity, magnetostatic equilibrium and degenerate core equation of state to obtain the structural properties of these stars.
• Although the Chandrasekhar mass limit is retained in the absence of magnetic field and irrespective of the luminosity, strong central fields of about $10^{14}\, {\rm G}$ can yield super-Chandrasekhar white dwarfs with masses up to $1.9\, M_{\odot}$.
• Smaller white dwarfs tend to remain super-Chandrasekhar for sufficiently strong central fields even when their luminosity is significantly suppressed to $10^{-16}\ L_{\odot}$.