Book contents
- Frontmatter
- Contents
- Preface to the Second Edition
- Preface to the First Edition, 2000
- Acknowledgments
- PART I Basic Phenomenology
- PART II Physical Models
- 6 Self-Gravity and Relation to Plasma Physics
- 7 Relaxation Times, Absence of Thermodynamical Equilibrium
- 8 Models
- 9 Equilibrium and Stability: Symmetry and Symmetry Breaking
- 10 Classical Ellipsoids
- 11 Introduction to Dispersive Waves
- 12 Jeans Instability
- PART III Spiral Galaxies
- PART IV Elliptical Galaxies
- PART V In Perspective
- Bibliography
- Index of objects
- Index
10 - Classical Ellipsoids
from PART II - Physical Models
Published online by Cambridge University Press: 05 June 2014
- Frontmatter
- Contents
- Preface to the Second Edition
- Preface to the First Edition, 2000
- Acknowledgments
- PART I Basic Phenomenology
- PART II Physical Models
- 6 Self-Gravity and Relation to Plasma Physics
- 7 Relaxation Times, Absence of Thermodynamical Equilibrium
- 8 Models
- 9 Equilibrium and Stability: Symmetry and Symmetry Breaking
- 10 Classical Ellipsoids
- 11 Introduction to Dispersive Waves
- 12 Jeans Instability
- PART III Spiral Galaxies
- PART IV Elliptical Galaxies
- PART V In Perspective
- Bibliography
- Index of objects
- Index
Summary
The themes introduced in Chapter 10 are demonstrated in one class of dynamical systems, which, because of its simplicity, serves as a bridge from the case of single-particle dynamics to the more complex collective behavior of continuous media. The study of incompressible self-gravitating fluids with ellipsoidal shape focuses on an environment with a limited number of degrees of freedom. Still it opens the way to several subtle phenomena that have attracted the interest of many eminent mathematicians and physicists, starting with Newton.
The classical ellipsoids were originally studied as models, as a starting point, to interpret the properties of rotating celestial bodies, such as planets and stars. Curiously, similar concepts have recently found applications in completely different fields, such as the physics of atomic nuclei and black holes. Tools related to the simple properties of ellipsoidal mass distributions have found applications in the study of the formation of structures by collapse (“pancakes” or protogalaxies) in the cosmological context.
In galactic dynamics, classical ellipsoids might be thought of as the natural representation of elliptical galaxies. Unfortunately, spectroscopic observations in the mid-1970s proved that bright ellipticals are not flattened by rotation and thus do not fit this simple picture (see Subsection 4.2.2 and Part IV).
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- Chapter
- Information
- Dynamics of Galaxies , pp. 105 - 118Publisher: Cambridge University PressPrint publication year: 2014