Rossby and Magnetic Prandtl Number Scaling of Stellar Dynamos
Abstract
Rotational scaling relationships are examined for the degree of equipartition between magnetic and kinetic energies in stellar convection zones. These scaling relationships are approached from two paradigms, with first a glance at scaling relationship built on an energy-balance argument and second a look at a force-based scaling. The latter implies a transition between a nearly constant inertial scaling when in the asymptotic limit of minimal diffusion and magnetostrophy, whereas the former implies a weaker scaling with convective Rossby number. Both scaling relationships are then compared to a suite of 3D convective dynamo simulations with a wide variety of domain geometries, stratifications, and range of convective Rossby numbers.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 2019
- DOI:
- 10.3847/1538-4357/ab14ea
- arXiv:
- arXiv:1904.00225
- Bibcode:
- 2019ApJ...876...83A
- Keywords:
-
- dynamo;
- magnetohydrodynamics: MHD;
- stars: magnetic field;
- stars: rotation;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 15 pages, 6 figures, accepted in ApJ