Rotating stellar models according to the quasi-dynamic method.
Abstract
A numerical scheme based on the quasi-dynamic method (QDM) of Rakavy, Shaviv, and Zinamon (1967) is developed. It is noted that the aim of the QDM for axisymmetric rotating stellar models is to solve the meridional equations describing the steady state of a rotating star for a given distribution of specific entropy and angular momentum. The quasi-dynamic equations are solved by an iterative scheme which converges after a sufficiently long quasi-time step to a solution of the meridional equations if and only if that solution is dynamically stable. The difference equations and the numerical scheme are described, calculation of the gravitational potential is outlined, and solution of the quasi-dynamic equations is demonstrated. A sequence of rotating polytropes with an index of 2 is calculated numerically as an illustration of the method. Instabilities which cannot be dealt with by the QDM are pointed out.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1976
- DOI:
- 10.1086/154443
- Bibcode:
- 1976ApJ...206..809K
- Keywords:
-
- Axisymmetric Bodies;
- Dynamic Stability;
- Stellar Models;
- Stellar Rotation;
- Angular Momentum;
- Convergence;
- Difference Equations;
- Equations Of State;
- Equilibrium Methods;
- Astrophysics