Cloud/particle model of the interstellar medium: Galactic spiral structure

Journal Article · Wed Apr 15 04:00:00 EST 1981 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/158823· OSTI ID:6338036

Levinson, F H; Roberts, Jr, W W

A cloud/particle model for gas flow in galaxies is developed. Instead of assuming that the interstellar medium is a continuum of gas governed by an equation of state, our model views it as a discrete system of dense clouds. We believe the real interstellar medium can be characterized by such a system with an average mean free path for the clouds of lambda/sub c/ = 100--200 pc. The model incorporates cloud-cloud collisions and supernovae as dominant local processes. The time evolution of the system of clouds is calculated in response to the gravitational field of a background spiral density wave in the model galactic disk. Cloud-cloud collisions are the principal means of dissipation. To counter this dissipation and maintain local dispersion, supernova explosions in the medium administer radial snowplow pushes to all nearby clouds. The causal link, as we see it, between these processes is that cloud-cloud collisions will form stars ad these same stars will rapidly become supernovae.

• Research Organization: Department of Astronomy, University of Virginia, Charlottesville
• OSTI ID: 6338036
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 245:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANNULAR SPACE
COLLISIONS
CONFIGURATION
COSMIC GASES
ERUPTIVE VARIABLE STARS
FLUID FLOW
FLUID MECHANICS
FLUIDS
GALAXIES
GAS FLOW
GASES
GRAVITATIONAL FIELDS
HYDRODYNAMICS
INTERSTELLAR SPACE
MEAN FREE PATH
MECHANICS
SHOCK WAVES
SPACE
STAR ACCRETION
STAR EVOLUTION
STARS
SUPERNOVAE
THREE-DIMENSIONAL CALCULATIONS
TWO-DIMENSIONAL CALCULATIONS
VARIABLE STARS