Astronomy and Astrophysics – Astronomy
Scientific paper
Jul 1990
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1990nascp3084..378r&link_type=abstract
In NASA, Ames Research Center, The Interstellar Medium in External Galaxies: Summaries of Contributed Papers p 378-380 (SEE N91-
Astronomy and Astrophysics
Astronomy
Active Galaxies, Carbon Monoxide, Excitation, Far Infrared Radiation, Galactic Radiation, Infrared Radiation, Luminosity, Molecular Clouds, Molecular Gases, Spiral Galaxies, Star Formation, Calibrating, Hydrogen, Milky Way Galaxy, Telescopes
Scientific paper
The correlation between the CO and far infrared luminosities of spiral galaxies is well established. The luminosity ration, LFIR/L sub CO in IR luminous active galaxies is, however, systematically five to ten times higher than in ordinary spirals and molecular clouds in our Galaxy. Furthermore, the masses of molecular hydrogen in luminous galaxies are large, M (H2) approx. equals 1010 solar magnitude, which indicates the observed luminosity ratios are due to an excess of infrared output, rather than a deficiency of molecular gas. These large amounts of molecular gas may fuel luminous galaxies through either star formation or nuclear activity. This interpretation rests on applying the M (H2)/LCO ratio calibrated in our Galaxy to galaxies with strikingly different luminosity ratios. But are the physical conditions of the molecular gas different in galaxies with different luminosity ratios. And, if so, does the proportionality between CO and H2 also vary among galaxies. To investigate these questions researchers observed CO (2 to 1) and (1 to 0) emission from four luminous galaxies with the Institute for Radio Astronomy in the Millimeter range (IRAM) 30 m telescope. Researchers conclude that most of the CO emission from these Arp 193, Arp 220, and Mrk 231 arises in regions with moderate ambient densities similar to the clouds in the Milky Way molecular ring. The emission is neither from dense hot cloud cores nor from the cold low density gas characteristic of the envelopes of dark clouds.
Downes Dennis
Radford Simon J. E.
Solomon Philip M.
No associations
LandOfFree
CO excitation in four IR luminous galaxies 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 CO excitation in four IR luminous galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and CO excitation in four IR luminous galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1096149