Bar-driven spiral density waves in galaxies

Journal Article · Thu Jul 01 04:00:00 EDT 1982 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/160056· OSTI ID:5031747

Schempp, W V

A series of two-dimensional hydrodynamical models is computed to test the gravitational response of a uniform, isothermal, massless gas disk to a uniformly rotating prolate potential. The parameters describing the mass distribution and rotation properties of the prolate bar are varied from model to model. The location and strength of the region in which hydrodynamic shocks are found are dependent on the radial distribution of mass within the bar and on the axial ratio of the bar potential. The radius of corotation determines whether the galaxy has a ''ring'' or ''spiral'' morphology. Most importantly, the range from barred, through intermediate cases, to nonbarred morphologies is proposed to be the consequence of variations in the amplitude of the prolate potential. A large-scale but weak bar (so weak that it might not be observed) can produce a two-armed spiral response in the gas. It is suggested that the full spectrum of normal two-armed trailing spiral patterns observed in galaxies may be produced by rotating barlike potentials.

• Research Organization: Institute for Astronomy, University of Hawaii
• OSTI ID: 5031747
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 258:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC GASES
FLUID MECHANICS
FLUIDS
GALAXIES
GASES
HYDRODYNAMICS
MASS
MATHEMATICAL MODELS
MATHEMATICS
MECHANICS
MORPHOLOGY
MOTION
NUMERICAL ANALYSIS
ROTATION
TWO-DIMENSIONAL CALCULATIONS