Post-dynamical inspiral phase of common envelope evolution. The role of magnetic fields

Abstract

During common envelope evolution, an initially weak magnetic field may undergo amplification by interacting with spiral density waves and turbulence generated in the stellar envelope by the inspiralling companion. Using 3D magnetohydrodynamical simulations on adaptively refined spherical grids with excised central regions, we studied the amplification of magnetic fields and their effect on the envelope structure, dynamics, and the orbital evolution of the binary during the post-dynamical inspiral phase. About $95\%$ of magnetic energy amplification arises from magnetic field stretching, folding, and winding due to differential rotation and turbulence while compression against magnetic pressure accounts for the remaining $\sim 5\%$. Magnetic energy production peaks at a scale of $3a_{\text{b}}$, where $a_{\text{b}}$ is the semimajor axis of the central binary's orbit. Because the magnetic energy production declines at large radial scales, the conditions are not favorable for the formation of magnetically collimated bipolar jet-like outflows unless they are generated on small scales near the individual cores, which we did not resolve. Magnetic fields have a negligible impact on binary orbit evolution, mean kinetic energy, and the disk-like morphology of angular momentum transport, but turbulent Maxwell stress can dominate Reynolds stress when accretion onto the central binary is allowed, leading to an $\alpha$-disk parameter of $\simeq 0.034$. Finally, we discovered accretion streams arising from the stabilizing effect of the magnetic tension from the toroidal field about the orbital plane, which prevents overdensities from being destroyed by turbulence and enables them to accumulate mass and eventually migrate toward the binary.

24 pages, 27 figures, Accepted for publication in Astronomy & Astrophysics

References in corpus (29)

• The Athena++ Adaptive Mesh Refinement Framework: Design and Magnetohydrodynamic Solvers
• Numerical simulations of quiet Sun magnetism: On the contribution from a small-scale dynamo
• Hydrodynamic turbulence cannot transport angular momentum effectively in astrophysical disks
• How mergers magnetise massive stars
• Angular Momentum Transport in Accretion Disks: Scaling Laws in MRI-driven Turbulence
• Hydrodynamic Torques in Circumbinary Accretion Disks
• The Triple-Ring Nebula around SN1987A: Fingerprint of a binary merger
• Asymmetric Accretion Flows within a Common Envelope
• Three Dimensional MHD Simulation of Circumbinary Accretion Disks -2. Net Accretion Rate
• On the Magnetic Prandtl Number Behavior of Accretion Disks
• Turbulent small-scale dynamo action in solar surface simulations
• Common envelope events with low-mass giants: understanding the transition to the slow spiral-in
• Episodic mass ejections from common-envelope objects
• Simulations of Magnetorotational Turbulence with a Higher-Order Godunov Scheme
• Magnetic Field Amplification During the Common Envelope Phase
• Energy transfer in compressible magnetohydrodynamic turbulence
• Mini-disk accretion onto spinning black hole binaries: quasi-periodicities and outflows
• Magnetorotational instability driven dynamos at low magnetic Prandtl numbers
• Simulating the formation of $\eta$ Carinae's surrounding nebula through unstable triple evolution and stellar merger-induced eruption
• Bipolar planetary nebulae from common envelope evolution of binary stars
• Common-envelope Dynamics of a Stellar-mass Black Hole: General Relativistic Simulations
• Common Envelope Shaping of Planetary Nebulae. III. The Launching of Jets in Proto-Planetary Nebulae
• Three-dimensional simulations of the jet feedback mechanism in common envelope jets supernova
• Post-dynamical inspiral phase of common envelope evolution: Binary orbit evolution and angular momentum transport
• Magnetic Flux Transport in Radiatively Inefficient Accretion Flows and the Pathway towards a Magnetically Arrested Disk
• Twin Jets and Close Binary Formation
• Grid-Based Simulations of Polar Circumbinary Disks: Polar Alignment and Vortex Formation
• Boundary Layers of Accretion Disks: Discovery of Vortex-Driven Modes and Other Waves
• On the origin of the lump in circumbinary discs

Cited by in corpus (6)

• Long-term Evolution of Binary Orbits Induced by Circumbinary Disks
• From spherical stars to disk-like structures: 3D common-envelope evolution of massive binaries beyond inspiral
• Large-scale ordered magnetic fields generated in mergers of helium white dwarfs
• Magnetically driven outflows in 3D common-envelope evolution of massive stars
• Journey to the center of the common envelope evolution. Inner dynamics of the post-dynamical inspiral
• Atmospheric Signatures of Common Envelope Evolution in White Dwarf Planets