Molecular Clouds Associated with Luminous Far-Infrared Sources in the Outer Galaxy
Abstract
The stellar content and physical properties of the molecular clouds associated with 21 bright far-IR sources in the outer Galaxy have been determined through C-12O, C-13O, 6-cm radio continuum, and IRAS observations. The molecular cloud masses range from 200 to about 10,000 solar masses. The far-IR luminosity-to-mass ratio for these clouds has a mean value of 6.8 solar luminosity/solar masses and shows no correlation with the cloud mass, a result similar to that found for more massive clouds in the inner Galaxy. The radio continuum survey of the 21 bright far-IR sources indicates that most of these regions probably have a single, massive star providing most of the ionization. The cloud masses derived from virial and LTE analyses are in agreement, supporting the assumptions commonly made in their calculations, and a tight, near-linear correlation is found between the C-12O luminosity and the cloud mass. The H2 column density and integrated C-12O intensity are also correlated on a point-by-point basis, although the scatter is larger than the C-12O luminosity-cloud mass relation.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1990
- DOI:
- 10.1086/169251
- Bibcode:
- 1990ApJ...362..147C
- Keywords:
-
- Far Infrared Radiation;
- Infrared Sources (Astronomy);
- Luminosity;
- Milky Way Galaxy;
- Molecular Clouds;
- Carbon Monoxide;
- Carbon 13;
- Infrared Astronomy Satellite;
- Interstellar Matter;
- Physical Properties;
- Astrophysics;
- GALAXIES: THE GALAXY;
- INTERSTELLAR: MOLECULES;
- INFRARED: SOURCES