Volume 427, Number 1, November III 2004
|Page(s)||279 - 292|
|Section||Stellar structure and evolution|
|Published online||25 October 2004|
Oscillations of magnetic stars*
II. Axisymmetric toroidal and non-axisymmetric shear Alfvén modes in a spherical shell
Laboratoire d'Astrophysique de Toulouse et Tarbes, Observatoire Midi-Pyrénées, 14 avenue É. Belin, 31400 Toulouse, France e-mail: firstname.lastname@example.org
Accepted: 16 July 2004
We carry out numerical and mathematical investigations of shear Alfvén waves inside of a spherical shell filled with an incompressible conducting fluid, and bathed in a strong dipolar magnetic field. We focus on axisymmetric toroidal and non-axisymmetric modes, in continuation of a previous work by Rincon & Rieutord (2003, A&A, 398, 663). Analytical expressions are obtained for toroidal eigenmodes and their corresponding frequencies at low diffusivities. These oscillations behave like magnetic shear layers, in which the magnetic poles play a key role, and hence become singular when diffusivities vanish. It is also demonstrated that non-axisymmetric modes are split into two categories, namely poloidal or toroidal types, following similar asymptotic behaviours as their axisymmetric counterparts when the diffusivities become arbitrarily small.
Key words: magnetohydrodynamics (MHD) / stars: oscillations / stars: magnetic fields
© ESO, 2004
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.