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Contents
After having studied this lecture, you should be able to
- to derive an estimate for the stellar dynamical relaxation time
in a spherical system of
stars.
- explain why we can describe the dynamics of elliptical galaxies
in terms of fluid equations.
- explain the difference in dynamics between an elliptical (hot
stellar system) and a spiral (cold, rotating stellar system)
- explain what is a continuity equation, and derive the
collisionless Boltzmann equation, Eq.(8.22), stating the
underlying assumptions.
- explain that the ellipticity of ellipticals does not results from
rotation, but from the anisotropy of the pressure tensor.
Tom Theuns
2003-04-28