Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Full Refereed Journal Article (PDF/Postscript)
· Full Refereed Scanned Article (GIF)
· References in the article
· Citations to the Article (64) (Citation History)
· Refereed Citations to the Article
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
On density waves in galaxies. I - Source terms and action conservation
Authors:
Mark, J. W.-K.
Affiliation:
AA(MIT, Cambridge, Mass.)
Publication:
Astrophysical Journal, vol. 193, Nov. 1, 1974, pt. 1, p. 539-559. (ApJ Homepage)
Publication Date:
11/1974
Category:
Astrophysics
Origin:
STI
NASA/STI Keywords:
Conservation Laws, Density Distribution, Galactic Structure, Space Density, Spiral Galaxies, Wave Propagation, Angular Momentum, Energy Transfer, Equilibrium Equations, Milky Way Galaxy, Resonance, Wave Dispersion, Wave Equations
DOI:
10.1086/153192
Bibliographic Code:
1974ApJ...193..539M

Abstract

The first in a series directed at mechanisms for the generation and maintenance of density waves in galaxies, this paper examines the problem of how source terms for wave action can actually be introduced into a modified action conservation principle. Generalized versions of the Lin-Shu dispersion relation and the Toomre-Shu conservation principle of wave action are derived which are valid even in the neighborhood of all the Lindblad resonances. Because of the finite radial epicyclic excursions of the resonant stars, each resonance influences a region on the order of one or two epicyclic distances. For our Galaxy, these are annular regions each several kiloparsecs in width. The proposed generalized dispersion relation gives finite wavenumbers throughout the resonance regions. Provided that there is not also a very rapid temporal decay in amplitude, both leading and trailing short waves are found to decay spatially in the direction of their respective group propagation. This decay process can be described physically in terms of the detailed balance of energy and angular momentum through a generalized conservation principle of wave action.

Printing Options

Print whole paper
Print Page(s) through

Return 600 dpi PDF to Acrobat/Browser. Different resolutions (200 or 600 dpi), formats (Postscript, PDF, etc), page sizes (US Letter, European A4, etc), and compression (gzip,compress,none) can be set through the Printing Preferences


More Article Retrieval Options

HELP for Article Retrieval
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints