Rotating white dwarf models with finite-temperature envelope

Abstract

We present new numerical method to compute structures of differentially rotating white dwarfs with thermal stratification. Our models have cores composed of ions and completely degenerate electrons and have isentropic envelopes composed of ions, photons, partially degenerate electrons and positrons. The models are intended to mimic very early phases of remnants of white dwarf binary mergers, some of which may lead to type Ia supernovae. The effect of hot envelope to increase the mass depends on its chemical composition through the mean molecular weight of the envelope. For uniformly rotating models, we see only a small increase in mass even in the presence of hot envelope. Differential rotation changes it drastically and super-Chandrasekhar mass model whose mass doubles the Chandrasekhar mass of the degenerate star for some parameter choices. We also compute quasi-equilibrium evolutionary sequences of remnants by fixing either total angular momentum or entropy in the envelope. Existence of these sequences depends on various factors such as the remnant mass, the profile of differential rotation, the entropy and the chemical composition of the envelope.

20 figures. Sec.4 has been totally revised. Accepted for publication in MNRAS

References in corpus (12)

• The separation distribution and merger rate of double white dwarfs: improved constraints
• The Viscous Evolution of White Dwarf Merger Remnants
• A systematic study of carbon-oxygen white dwarf mergers: mass combinations for Type Ia supernovae
• The Galactic Gravitational wave foreground
• Post-merger evolution of carbon-oxygen + helium white dwarf binaries and the origin of R Coronae Borealis and extreme helium stars
• A Refined Search for Pulsations in White Dwarf Companions to Millisecond Pulsars
• Origin of the early-type R stars: a binary-merger solution to a century-old problem?
• On the angular momentum evolution of merged white dwarfs
• General Relativistic White Dwarfs and Their Astrophysical Implications
• A Numerical Method for Generating Rapidly Rotating Bipolytropic Structures in Equilibrium
• Electromagnetic emission of white dwarf binary mergers
• On the Maximum Mass of General Relativistic Uniformly Rotating White Dwarfs

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