CO observations of infrared bright galaxies - The efficiency of star formation

Abstract

The authors have detected CO emission in each of 14 of the infrared bright galaxies listed on IRAS Circular 15 using the 14 m millimeter telescope of the FCRAO. They have compared the total CO luminosity for each galaxy with its IR luminosity and found a correlation of the two which also depends on the temperature of the dust. The authors present a simple model for the CO and IR emission, and deduce that most of the IR flux in these galaxies originates in molecular clouds and is related to star formation. It is found that the efficiency of star formation may vary by almost two orders of magnitude from galaxy to galaxy. Galaxies which have been previously identified as mergers are among those with the highest observed star formation efficiencies and dust temperatures.