Violent relaxation and dissipationless collapse

Journal Article · Sat Sep 01 04:00:00 EDT 1984 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/162386· OSTI ID:6249381

Villumsen, J V

A set of N-body simulations of dissipationless gravitational collapses of protogalactic systems was performed. The initial systems were either spheres, disks, or bars. All the initial systems were uniform density with solid body rotation. For the spheres, disks, and bars there is a sequence of models with different amounts of random kinetic energy and angular momentum. These sequences of models permit comparisons between systems with the same shape but different velocity distributions, and vice versa. The spherical collapses are regular, with no significant substructure forming. They lead to systems that do not resemble elliptical galaxies. They are too diffuse, with the wrong density profile and too much rotation. The nonspherical collapses are chaotic, with significant growth of substructure. The final systems resemble elliptical galaxies. They have approximately r/sup 1/4/ surface density profiles, and rotation is not dynamically significant.

• Research Organization: Institute for Advanced Study
• OSTI ID: 6249381
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 284:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANGULAR MOMENTUM
COMPUTERIZED SIMULATION
DIFFERENTIAL EQUATIONS
ENERGY
EQUATIONS
EQUATIONS OF MOTION
GALACTIC EVOLUTION
GALAXIES
GRAVITATIONAL COLLAPSE
KINETIC ENERGY
MANY-BODY PROBLEM
MORPHOLOGY
PARTIAL DIFFERENTIAL EQUATIONS
POISSON EQUATION
SIMULATION