One-Armed Spiral Instability in Double-Degenerate Post-Merger Accretion Disks

Abstract

Increasing observational and theoretical evidence points to binary white dwarf mergers as the origin of some if not most normal Type Ia supernovae (SNe Ia). In this paper, we discuss the post-merger evolution of binary white dwarf (WD) mergers, and their relevance to the double-degenerate channel of SNe Ia. We present 3D simulations of carbon-oxygen (C/O) WD binary systems undergoing unstable mass transfer, varying both the total mass and the mass ratio. We demonstrate that these systems generally give rise to a one-armed gravitational spiral instability. The spiral density modes transport mass and angular momentum in the disk even in the absence of a magnetic field, and are most pronounced for secondary-to-primary mass ratios larger than $0.6$. We further analyze carbon burning in these systems to assess the possibility of detonation. Unlike the case of a $1.1+1.0M_{\odot }$ C/O WD binary, we find that WD binary systems with lower mass and smaller mass ratios do not detonate as SNe Ia up to $\sim 8-22$ outer dynamical times. Two additional models do however undergo net heating, and their secular increase in temperature could possibly result in a detonation on timescales longer than those considered here.

Accepted to Astrophysical Journal

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Cited by in corpus (12)

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• Double-Degenerate Carbon-Oxygen and Oxygen-Neon White Dwarf Mergers: A New Mechanism for Faint and Rapid Type Ia Supernovae
• Three-Dimensional Simulation of Double-Detonations in the Double-Degenerate Model for Type Ia Supernovae and Interaction of Ejecta with a Surviving White Dwarf Companion
• Near-Chandrasekhar-Mass Type Ia Supernovae from the Double-Degenerate Channel
• Common envelope to explosion delay time of type Ia supernovae
• Multimessenger Emission from the Accretion Induced Collapse of White Dwarfs
• Common envelope to explosion delay time distribution (CEEDTD) of type Ia supernovae
• Rotating white dwarf models with finite-temperature envelope
• Probe for Type Ia supernova progenitor in decihertz gravitational wave astronomy
• Decihertz gravitational waves from double white dwarf merger remnants
• Revealing Phase Transition in Dense Matter with Gravitational Wave Spectroscopy of Binary Neutron Star Mergers
• General-relativistic resistive-magnetohydrodynamics simulations of self-consistent magnetized rotating neutron stars