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 (54) (Citation History)
· Refereed Citations to the Article
· Also-Read Articles (Reads History)
· Translate This Page
Stability of nonrotating stellar systems. II - Prolate shell-orbit models
Merritt, David; Hernquist, Lars
AA(Rutgers University, Piscataway, NJ), AB(Institute for Advanced Study, Princeton, NJ)
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 376, Aug. 1, 1991, p. 439-457. Research supported by University of California and Pittsburgh Supercomputing Center. (ApJ Homepage)
Publication Date:
NASA/STI Keywords:
Galactic Rotation, Galactic Structure, Shell Galaxies, Stellar Systems, Astronomical Models, Galactic Evolution, Many Body Problem, Systems Stability
Bibliographic Code:


The dynamical stability of nonrotating prolate galaxy models constructed from thin long-axis tube orbits ('shell' orbits) are investigated. Models more elongated than about E6 (axis ratio of about 2:5) are unstable to bending modes than rapidly increase the velocity dispersion perpendicular to the long axis and decrease the model's elongation. Approximate representations of the spatial forms of the fastest growing modes and their growth rates are obtained. Most of the evolution is due to two modes: a symmetric (banana-shaped) bending and an antisymmetric (S-shaped) bending. The instability is similar to the 'firehose' instability of a thin self-gravitating slab, except that it persists in models with velocity anisotropies that are much less extreme than the critical value for instability of the slab. A simple model is given that reproduces the basic features of the instability in the prolate geometry. These results provide support for the hypothesis of Fridman and Polyachenko (1984) that the absence of elliptical galaxies flatter than about E6 is due to dynamical instability.

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