Waves in the radiative zones of rotating magnetized stars

Service AstroPhysique (Sap), IRFU, CEA Saclay : A.Valade, V.Prat, S.Mathis, K.Augustson
Centre Blaise Pascal : Emmanuel Quémener

To have a full understanding of the dynamics of stellar and planetary systems, we cannot consider them as only interacting rotating solid bodies. Indeed, a more nuanced approach includes the interactions through processes such as internal energy dissipation due to tidal coupling between the star and its planets, and even between the planets themselves.

The studies of these internal waves have now reached a level of accuracy that leads us to consider low amplitude but complex magnetic fields. We thus aim to develop an asymptotic short-wavelength theory for waves in radiative zones of rotating stars with a general magnetic field topology. Such a theory permits the characterization of fossil magnetic fields inside of the star, whereas they are normally observable only at the star's surface.

A dispersion relationship has already been derived for a uniformly rotating polytropic star with a low Alfvén speed. Two families of waves are evident in the analysis: gravito-inertial waves perturbed by a magnetic field and Alfvén waves perturbed by gravity and rotation. We now aim to explore the parameter space for such waves in this model with a Hamiltonian ray-tracing method. This numerical approach consists of following the paths of rays in the interior of a star, and then analyzing their characteristics through various representations: as plots of their spatial trajectories, phase-space diagrams (more widely known as Poincaré sections), and describing zones where the waves are able to propagate. Most of these analyses require the computation of a large number of rays, leading us to use parallel computing methods on supercomputers.

Contribution du CBP

Le Centre Blaise Pascal met à disposition son plateau technique multi-shaders pour :

  • offrir un large panel de types de clusters
  • évaluer l'intégration de traitements automatisés sur le plateau technique multi-noeuds
recherche/projets/wavesmagnetizedstars.txt · Dernière modification: 2018/06/14 10:51 par equemene