Non-adiabatic tidal forcing of a massive, uniformly rotating star - II. The low-frequency, inertial regime
Abstract
We study the fully non-adiabatic tidal response of a uniformly rotating unevolved 20-Msolar star to the dominant l=m=2 component of the perturbing potential of the companion. This is done numerically with a 2D implicit finite difference scheme. We assume the star is rotating slowly with angular speed Omega_s<=Omega_c, so that the centrifugal force can be neglected, but the Coriolis force is taken fully into account. We study the low-frequency `inertial' regime |sigma^-|<2Omega_s, where sigma^- is the forcing frequency in the frame rotating with the stellar spin rate Omega_s. In this frequency range inertial modes are excited in the convective core which can interact with rotationally modified g or r modes in the radiative envelope and cause significant strengthening of the tidal interaction. Resonant interaction with quasi-toroidal (r) modes in slightly supersynchronous stars causes efficient spin-down towards corotation. We determine time-scales for tidal spin-up and spin-down in the inertial frequency regime for stars spinning with Omega_s=0.1Omega_c and 0.2Omega_c.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 1997
- DOI:
- 10.1093/mnras/291.4.633
- arXiv:
- arXiv:astro-ph/9706186
- Bibcode:
- 1997MNRAS.291..633S
- Keywords:
-
- Binary Stars;
- Early Stars;
- Stellar Rotation;
- Tides;
- Stellar Mass;
- Coriolis Effect;
- Astrophysics;
- HYDRODYNAMICS;
- STARS: ATMOSPHERES;
- BINARIES: CLOSE;
- STARS: OSCILLATIONS;
- STARS: ROTATION;
- Astrophysics
- E-Print:
- 21 pages, 12 Postscript figures, accepted by MNRAS