Astronomy and Astrophysics – Astrophysics
Scientific paper
Aug 1991
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1991apj...376..439m&link_type=abstract
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 376, Aug. 1, 1991, p. 439-457. Research supported by University of Californ
Astronomy and Astrophysics
Astrophysics
50
Galactic Rotation, Galactic Structure, Shell Galaxies, Stellar Systems, Astronomical Models, Galactic Evolution, Many Body Problem, Systems Stability
Scientific paper
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.
Hernquist Lars
Merritt David
No associations
LandOfFree
Stability of nonrotating stellar systems. II - Prolate shell-orbit models does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Stability of nonrotating stellar systems. II - Prolate shell-orbit models, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stability of nonrotating stellar systems. II - Prolate shell-orbit models will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1725026