Astronomy and Astrophysics – Astrophysics
Scientific paper
Oct 1992
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992a%26a...264..433b&link_type=abstract
Astronomy and Astrophysics (ISSN 0004-6361), vol. 264, no. 2, p. 433-443.
Astronomy and Astrophysics
Astrophysics
120
Carbon Monoxide, Interstellar Gas, Molecular Spectra, Radio Spectra, Spiral Galaxies, Molecular Energy Levels, Optical Thickness
Scientific paper
The analysis of the CO(1-0) and CO(2-1) survey of nearby galaxies carried out at the IRAM 30-m telescope Braine et al. (1992) is presented. Galaxies showing signs of morphological disturbance are found to have more central CO emission than unperturbed systems. The line ratio in galactic nuclei (0.89 +/- 0.06) is consistent with optically thick gas with Tex of about 10 to 20 K in both transitions being the dominant component of the molecular interstellar medium in the nuclei and/or nuclear rings. Gas heating through collisions with the dust grains yields temperatures in accord with the present observations. That only one M82-like galaxy was found is further evidence that such intense starbursts are rare and/or short-lived compared to the signs of disturbance. A simple model is presented in which clouds are externally heated and optically thick in both the Co(1-0) and CO(2-1) lines and where the line ratio can be significantly greater than unity. The line and IRAS S60/S100 ratios are not strongly correlated but show the same trends when galaxies are averaged together.
Braine Jonathan
Combes François
No associations
LandOfFree
A CO(1-0) and CO(2-1) survey of nearby spiral galaxies. II - Physical conditions in the nuclear gas does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A CO(1-0) and CO(2-1) survey of nearby spiral galaxies. II - Physical conditions in the nuclear gas, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A CO(1-0) and CO(2-1) survey of nearby spiral galaxies. II - Physical conditions in the nuclear gas will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1868445