Magnetized Moving Mesh Merger of a Carbon-Oxygen White Dwarf Binary

Chenchong Zhu; Rudiger Pakmor; Marten H. van Kerkwijk; Philip Chang

doi:10.1088/2041-8205/806/1/L1

paper

Magnetized Moving Mesh Merger of a Carbon-Oxygen White Dwarf Binary

arXiv:1504.01732 · doi:10.1088/2041-8205/806/1/L1

Abstract

White dwarf (WD) binary mergers are possible progenitors to a number of unusual stars and transient phenomena, including type Ia supernovae. To date, simulations of mergers have not included magnetic fields, even though they are believed to play a significant role in the evolution of the merger remnant. We simulated a 0.625 - 0.65 $M_{⊙}$ carbon-oxygen WD binary merger in the magnetohydrodynamic moving mesh code Arepo. Each WD was given an initial dipole field with a surface value of $\sim 1 0^{3}$ G. As in simulations of merging double neutron star binaries, we find exponential field growth within Kelvin-Helmholtz instability-generated vortices during the coalescence of the two stars. The final field has complex geometry, and a strength $> 1 0^{10}$ G at the center of the merger remnant. Its energy is $\sim 2 \times 1 0^{47}$ ergs, $\sim 0.2$ % of the remnant's total energy. The strong field likely influences further evolution of the merger remnant by providing a mechanism for angular momentum transfer and additional heating, potentially helping to ignite carbon fusion.

arXiv comment5 pages, 4 figures, submitted to ApJ 7 April 2015

Magnetized Moving Mesh Merger of a Carbon-Oxygen White Dwarf Binary

Abstract

References in corpus (32)

Cited by in corpus (33)