The effects of vertical outflows on disk dynamos

Abstract

We consider the effect of vertical outflows on the mean-field dynamo in a thin disk. These outflows could be due to winds or magnetic buoyancy. We analyse both two-dimensional finite-difference numerical solutions of the axisymmetric dynamo equations and a free-decay mode expansion using the thin-disk approximation. Contrary to expectations, a vertical velocity can enhance dynamo action, provided it is not too strong. In the nonlinear regime this can lead to super-exponential growth of the magnetic field.

14 pages, final version after referee comments, accepted in A&A

References in corpus (1)

• The inverse cascade and nonlinear alpha-effect in simulations of isotropic helical hydromagnetic turbulence

Cited by in corpus (19)

• Astrophysical magnetic fields and nonlinear dynamo theory
• Galactic dynamo and helicity losses through fountain flow
• IMAGINE: A comprehensive view of the interstellar medium, Galactic magnetic fields and cosmic rays
• Structured outflow from a dynamo active accretion disc
• Outflows and accretion in a star--disc system with stellar magnetosphere and disc dynamo
• Accretion of a massive magnetized torus on a rotating black hole
• Modelling MHD accretion-ejection - episodic ejections of jets triggered by a mean-field disk dynamo
• Non-linear galactic dynamos: A toolbox
• A physical approach to modelling large-scale galactic magnetic fields
• On the origin of warps and the role of the intergalactic medium
• Wobbling and precessing jets from warped disks in binary systems
• Relativistic outflows from a GRMHD mean-field disk dynamo
• MHD accretion-ejection: jets launched by a non-isotropic accretion disk dynamo. II. A dynamo tensor defined by the disk Coriolis number
• MHD accretion-ejection: jets launched by a non-isotropic accretion disk dynamo. I. Validation and application of selected dynamo tensorial components
• Jets from accretion disk dynamos: consistent quenching modes for dynamo and resistivity
• Turbulent protostellar discs
• Supernova-driven interstellar turbulence and the galactic dynamo
• Magnetic field amplification by SN-driven interstellar turbulence
• Outflows from dynamo-active protostellar accretion discs