EDP Sciences
Free access
Issue
A&A
Volume 440, Number 2, September III 2005
Page(s) 653 - 666
Section Stellar structure and evolution
DOI http://dx.doi.org/10.1051/0004-6361:20052640


A&A 440, 653-666 (2005)
DOI: 10.1051/0004-6361:20052640

Transport and mixing in the radiation zones of rotating stars

II. Axisymmetric magnetic field
S. Mathis and J.-P. Zahn

LUTH, Observatoire de Paris, 92195 Meudon, France
    e-mail: [stephane.mathis;jean-paul.zahn]@obspm.fr

(Received 4 January 2005 / Accepted 11 May 2005 )

Abstract
The purpose of this paper is to improve the modeling of the mixing of chemical elements that occurs in stellar radiation zones. In addition to the classical rotational mixing considered in our previous paper, which results of the combined action of the thermally-driven meridional circulation and of the turbulence generated by the shear of differential rotation, we include here the effect of an axisymmetric magnetic field in a self-consistent way. We treat the advection of the field by the meridional circulation, its Ohmic diffusion, and the production of its toroidal component through the shear of differential rotation. The Lorentz force is assumed not to exceed the centrifugal force; it acts on the baroclinic balance and therefore on the meridional flow, and it has a strong impact on the transport of angular momentum. All variables and governing equations are expanded in spherical or spherical vectorial functions, to arbitrary order: this yields a system of partial differential equations in time and in the radial coordinate, which is ready to be implemented in a stellar structure code.


Key words: magnetohydrodynamics (MHD) -- turbulence -- stars: rotation -- stars: magnetic fields -- stars: evolution




© ESO 2005