Analysis of 12CO and 13CO Emission in a 3 Square Degree Region of the Galactic Plane between L = 23 degrees and 25 degrees
Abstract
A 3-sq deg section of the inner Galactic plane centered at l = 24 deg, b = 0 deg in both (C-13)O and CS. The observations were supplemented by preexisting CO data from the Massachusetts-Stony Brook Galactic plane survey. It was possible to identify 47 molecular clouds in the region surveyed. Distances to the clouds were assigned using a size-line width relation which was derived for a set of calibrator clouds at known distances. By combining the CO and (C-13)O data, it was possible to calculate LTE masses for the clouds and to compare them with masses estimated from the virial theorem. Masses estimated from the two methods are tightly correlated, suggesting that the clouds observed in this study are close to virial equilibrium. The masses derived using the two methods are in reasonable agreement. Little CS emission was detected in this section or the Galactic plane; averaged over the region of the survey, the CO/CS integrated intensity ratio is found to be 660 + or - 160, considerably larger than the ratio in the Galactic center.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1990
- DOI:
- 10.1086/168786
- Bibcode:
- 1990ApJ...355..536L
- Keywords:
-
- Carbon Monoxide;
- Emission Spectra;
- Molecular Clouds;
- Sky Surveys (Astronomy);
- Abundance;
- Astronomical Catalogs;
- Density Distribution;
- Luminosity;
- Milky Way Galaxy;
- Spectral Line Width;
- Astrophysics;
- INTERSTELLAR: ABUNDANCES;
- INTERSTELLAR: MOLECULES