Effects of dissipation on the gas response to oval distortions of disk galaxies

Journal Article · Tue Nov 01 04:00:00 EST 1977 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/155637· OSTI ID:5280974

Sanders, R H

The time-dependent response of a ensemble of noninteracting test particles to a rotating oval distortion of a realistic axisymmetric galactic disk is numerically calculated for several assumed values of the distortion angular velocity. The test-particle response is found to be barlike and to strongly reinforce the imposed perturbation if the angular velocity of the distortion permits only one inner Lindblad resonance. The calculations are then repeated, with the mass of each particle distributed over some sufficiently large volume. In such a representation, the test particles become fluid elements in a Lagrangian sense, and an artificial viscosity may be defined in the usual manner. If this bulk viscosity is the only gas dynamical effect considered, the ''gas'' responds to the rotating oval distortion by forming a material bar inside the inner resonance and trailing spiral density waves beyond the resonance. It is only the dissipation provided by the artificial viscosity which distinguishes the bar response of the stars from the bar-plus-spiral-density waves of the gas response.

• Research Organization: European Southern Observatory, Geneva
• OSTI ID: 5280974
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 217:3; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANGULAR VELOCITY
FLUID FLOW
FLUID MECHANICS
GALAXIES
GRAVITATIONAL FIELDS
HYDRODYNAMICS
MECHANICS
MOTION
ROTATION
VELOCITY
VISCOSITY