Density wave induced star formation: The optical surface brightness of galaxies

Journal Article · Mon Oct 15 04:00:00 EDT 1979 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/157413· OSTI ID:5857992

Bash, F N

A model for the galactic orbits of molecular clouds has been devised. The molecular clouds are assumed to be launched from the two-armed spiral-shock wave, to orbit in the Galaxy like ballistic particles with gravitational perturbations due to the density-wave spiral-potential, and each cloud is assumed to produce a cluster of stars. Each cloud radiates detectable /sup 12/C/sup 16/O (J=0..-->..1) spectral line radiation from birth for 40 million years. Stars are seen in the cloud about 25 million years after birth, and the star cluster is assumed to continue in ballistic orbit around the Galaxy.The model has been tested by comparing its predicted velocity-longitude diagram for CO against that observed for the Galaxy and by comparing the model's predicted distribution of light in the UBV photometric bands against observed surface photometry for Sb and SC galaxies. The interpolation of the initial velocities in the model was corrected, and the model was examined to see whether preshock or postshock initial velocities better fit the observations. The model gives very good general agreement and reproduces many of the features observed in the CO velocity-longitude diagram.

• Research Organization: Department of Astronomy, The University of Texas at Austin
• OSTI ID: 5857992
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 233:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
GALAXIES
INTERSTELLAR SPACE
MILKY WAY
MOLECULES
OXIDES
OXYGEN COMPOUNDS
PHOTOMETRY
SHOCK WAVES
SPACE
STAR ACCRETION
STAR CLUSTERS
STAR EVOLUTION
VELOCITY