Spiral structure and star formation. II. Stellar lifetimes and cloud kinematics

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

DOI:https://doi.org/10.1086/162181· OSTI ID:6126452

Hausman, M A; Roberts, Jr, W W

We present further results of our model, introduced in Paper I, of star formation and star-gas interactions in the cloud-dominated ISMs of spiral density wave galaxies. The global density distribution and velocity field of the gas clouds are virtually independent of stellar parameters and even of mean free path for the wide range of values studied, but local density variations are found which superficially resemble cloud complexes. Increasing the average life span of ''spiral tracer'' stellar associations beyond about 20 Myr washes out the spiral pattern which younger associations show. Allowing clouds to form several successive associations (sequential star formation) slightly increases the frequency of interarm, young-star spurs and substantially increases the average star formation rate. The mean velocity field of clouds shows tipped oval streamlines, similar to both continuum gas dynamical models and stellar-kinematic models of spiral density waves. These streamlines are almost ballistic orbits except close to the spiral arms. Newly formed stellar associations leave the spiral density peak with initial tangential velocitie shigher than ''postshock'' values and do not fall back into the ''preshock'' region. By varying our stellar parametes within physically reasonable limits, we may reproduce spiral galaxies with a wide range of morphological appearaces.

• Research Organization: Department of Applied Mathematics and Computer Science, University of Virginia, Charlottesville
• OSTI ID: 6126452
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 282:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COLLISIONS
CONFIGURATION
COSMIC GASES
DYNAMICS
ERUPTIVE VARIABLE STARS
FLUIDS
GALAXIES
GASES
GRAVITATIONAL FIELDS
MANY-BODY PROBLEM
MATHEMATICAL MODELS
MEAN FREE PATH
MECHANICS
MORPHOLOGY
PARTICLE KINEMATICS
SPIRAL CONFIGURATION
STAR ACCRETION
STAR EVOLUTION
STARS
SUPERNOVAE
VARIABLE STARS