The Structure, Stability, and Dynamics
of Self-Gravitating Systems

Joel E. Tohline


About this Book
November 18, 1994

Much of our present, basic understanding of the structure, stability, and dynamical evolution of individual stars, short-period binary star systems, and the gaseous disks that are associated with numerous types of stellar systems (including galaxies) is derived from an examination of the behavior of a specific set of coupled, partial differential equations. These equations -- most of which also are heavily utilized in studies of continuum flows in terrestrial environments -- are thought to govern the underlying physics of all macroscopic "fluid" systems in astronomy. Although relatively simple in form, they prove to be very rich in nature.

The literature on this subject is enormous, as serious discussions of the structure and dynamical properties of stars and galaxies date back more than a century. Although a reasonable attempt is made here to review this vast literature and to provide a bridge between discussions that traditionally have focused on stellar structure and those that have focused on galaxy disks, the primary purpose of this work is two-fold:

To document in an electronically accessible format many of the key physical principles that underlie modern discussions of the structure, stability, and dynamical evolution of astrophysical fluid systems;

To take advantage of the added dimensions offered by the hypertext medium -- such as color, text/equation linkages, animation, VRML, and access to online computational algorithms -- to effectively illustrate many of these physical principles.

A distinct advantage afforded by the development of an on-line electronic manuscript is the opportunity hypertext offers to continually expand or modify the manuscript's contents. This opportunity simultaneously poses a potential frustration to the reader (e.g., the manuscript may forever be in "draft" form). With this in mind, every effort will be made not to bring chapters on-line until they have been thoroughly checked for inconsistencies and errors, and to be responsive to constructive comments and criticisms. To assist readers/users in tracking new material, we have included near the top of each page a date showing when material on the page was last modified. To assist users in locating discussions of any topical material, we have included an online search engine that serves as a complete text index.

Joel E. Tohline
Department of Physics & Astronomy
Louisiana State University
Baton Rouge, LA 70803-4001

About Greek Symbols in this Book

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In order to view the common Greek letters and symbols which appear in various mathematical formulas of this book, you must select "Western (MacRoman)" as the choice of document encoding for your browser. Another suggestion we make is to set your browser to NOT underline any links. This is because most of the variables and symbols in the book are linked to a definitions page, and by not underlining the links, the symbols will be easier to recognize.
Other platforms: Netscape Communicator 4.0 is supposed to be able to handle the greek letters in this book. However, instead of seeing the proper Greek variables, you may view an array of garbage and funny little characters that normally do not appear in the more popular mathematical expressions. Please bare with us while we look for ways to correct this problem.

Special Features of this Book

Home Page | Preface | Context | Applications | Appendices | Search Index