# Simulations of Core Convection in Rotating A-Type Stars: Magnetic Dynamo Action

@article{Brun2005SimulationsOC, title={Simulations of Core Convection in Rotating A-Type Stars: Magnetic Dynamo Action}, author={Allan Sacha Brun and Matthew Keith Morris Browning and J. Toomre}, journal={The Astrophysical Journal}, year={2005}, volume={629}, pages={461-481} }

Core convection and dynamo activity deep within rotating A-type stars of 2 M☉ are studied with three-dimensional nonlinear simulations. Our modeling considers the inner 30% by radius of such stars, thus capturing within a spherical domain the convective core and a modest portion of the surrounding radiative envelope. The magnetohydrodynamic (MHD) equations are solved using the anelastic spherical harmonic (ASH) code to examine turbulent flows and magnetic fields, both of which exhibit intricate…

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## References

SHOWING 1-10 OF 53 REFERENCES

Global-Scale Turbulent Convection and Magnetic Dynamo Action in the Solar Envelope

- Physics
- 2004

The operation of the solar global dynamo appears to involve many dynamical elements, including the generation of fields by the intense turbulence of the deep convection zone, the transport of these…

Simulations of Core Convection in Rotating A-Type Stars: Differential Rotation and Overshooting

- Physics
- 2003

We present the results of three-dimensional simulations of core convection within A-type stars of 2 M☉, at a range of rotation rates. We consider the inner 30% by radius of such stars, thereby…

On the interaction between differential rotation and magnetic fields in the Sun

- Physics
- 2004

We have performed 3-D numerical simulations of compressible convection under the influence of rotation and magnetic fields in spherical shells. They aim at understanding the subtle coupling between…

Looking deep within an A-type star: Core convection Under the influence of rotation

- Physics
- 2003

The advent of massively parallel supercomputing has begun to per- mit explicit 3-D simulations of turbulent convection occurring within the cores of early-type main sequence stars. Such studies…

Turbulent Convection under the Influence of Rotation: Sustaining a Strong Differential Rotation

- Physics
- 2002

The intense turbulence present in the solar convection zone is a major challenge to both theory and simulation as one tries to understand the origins of the striking differential rotation profile…

Turbulent Solar Convection and its Coupling with Rotation

- Physics
- 1998

The dynamics of the vigorous convection in the outer envelope of the Sun must determine the transport of energy, angular momentum, and magnetic fields and must therefore be responsible for the…

Magnetic structures in a dynamo simulation

- Physics
- 1996

We use three-dimensional simulations to study compressible convection in a rotating frame with magnetic fields and overshoot into surrounding stable layers. The, initially weak, magnetic field is…

Solar Interface Dynamos. II. Linear, Kinematic Models in Spherical Geometry

- Physics
- 1997

Numerical models of interface dynamos are constructed, and their properties discussed in some detail. These models are extensions in spherical geometry of the Cartesian interface models considered by…

Magnetic fields in massive stars: dynamics and origin

- Physics
- 2004

Evidence continues to accumulate in favour of the presence of magnetic fields on the surfaces of massive stars. Some authors hypothesize that such fields originate in a dynamo in the convective core,…

Dynamo action by differential rotation in a stably stratified stellar interior

- Physics
- 2002

Magnetic fields can be created in stably stratified (non-convective) layers in a differentially rotating star. A magnetic instability in the toroidal field (wound up by differential rotation)…