CO in Optically Selected Starburst Galaxies
Abstract
We conducted a survey of J = 1 approaches 0 CO emission from a sample of optically selected starburst galaxies, most of which are Markarian galaxies. The sample galaxies have a similar ratio of CO luminosity to blue luminosity as galaxies previously detected in CO. The ratio of CO to H I luminosity is also similar for starburst galaxies as for galaxies previously detected in CO, although the starburst sample shows marginal evidence for an increase in this ratio by a factor of 2.6. If CO luminosity traces molecular mass, the Markarian starburst galaxies have the same amount of molecular gas (within a factor of 3) as normal spirals. The starburst may then result from an enhanced local efficiency of converting molecular gas to stars rather than a global increase in the amount of molecular fuel. The infrared-to-CO luminosity ratio in starburst galaxies is similar to that in isolated spirals and smaller than that in strongly interacting spirals. If this ratio measures star formation efficiency, then there is no global increase in star formation efficiency in these galaxies, and the starburst must be restricted to a small nuclear region. Since the global properties of the sample galaxies do not seem to vary widely from those of normal spirals, the Markarian starburst galaxies probably represent smaller scale starbursts than those in strongly interacting galaxies.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1989
- DOI:
- 10.1086/167139
- Bibcode:
- 1989ApJ...337..680J
- Keywords:
-
- Carbon Monoxide;
- Emission Spectra;
- Markarian Galaxies;
- Starburst Galaxies;
- Brightness Distribution;
- Galactic Nuclei;
- Luminosity;
- Spiral Galaxies;
- Star Formation;
- Astrophysics;
- GALAXIES: INTERSTELLAR MATTER;
- GALAXIES: STELLAR CONTENT