A Study of Molecular Gas in the Center of the S0 Galaxy NGC 4710
Abstract
This paper discusses observations of the J = 2-1 transition of ^12^CO and ^13^CO in the center of the Virgo Cluster S0 galaxy NGC 4710. We use a simple model suggested by Wrobel & Kenney (1992) for the distribution of molecular gas to obtain a value for the intensity ratio of the transitions J = 2-1 and J = 1-0 which is similar to that in other S0 galaxies and in spirals. Available information on the intensity ratio ^12^CO/^13^CO suggests that the molecular gas is optically thick. This assumption is used to set limits on the gas temperature which are consistent with values typical of the Milky Way. The line profile observed at the center of the galaxy is complex, indicating the presence of significant structure within the source. This profile is well reproduced by adding a small number of clouds to the model. Although present data do not constrain the cloud properties, those clouds we employ are analogs of large Milky Way giant molecular clouds and contribute ~25% of the total mass of the molecular disk in the center of this galaxy. The model closely constrains the locations of clouds which produce structure at the red and blue ends of our line profile. Differences in the shapes of the profiles in the J = 1-0 and J = 2-1 transitions can be qualitatively explained by the lack of cloudy structure within part of the molecular disk northeast of the nucleus.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1994
- DOI:
- 10.1086/174183
- Bibcode:
- 1994ApJ...427..770W
- Keywords:
-
- Astronomical Models;
- Astronomical Spectroscopy;
- Electron Transitions;
- Interstellar Gas;
- Molecular Clouds;
- Molecular Gases;
- Molecular Spectra;
- Spiral Galaxies;
- Elliptical Galaxies;
- Gas Temperature;
- Kinematics;
- Velocity;
- Virgo Galactic Cluster;
- Astrophysics;
- GALAXIES: ELLIPTICAL AND LENTICULAR;
- CD;
- GALAXIES: INDIVIDUAL NGC NUMBER: NGC 4710;
- GALAXIES: ISM;
- ISM: MOLECULES