Description
We present results of a ^12^COJ=3-2 survey of 125 nearby galaxies obtained with the 10m Heinrich Hertz Telescope, with the aim to characterize the properties of warm and dense molecular gas in a large variety of environments. With an angular resolution of 22", ^12^CO3-2 emission was detected in 114 targets. Based on 61 galaxies observed with equal beam sizes the ^12^CO3-2/1-0 integrated line intensity ratio R_31_ is found to vary from 0.2 to 1.9, with an average value of 0.81. No correlations are found for R_31_ to Hubble-type and far-infrared luminosity. Possible indications for a correlation with inclination angle and the 60um/100um color temperature of the dust are not significant. Higher R_31_ ratios than in "normal" galaxies, hinting at enhanced molecular excitation, may be found in galaxies hosting active galactic nuclei. Even higher average values are determined for galaxies with bars or starbursts, the latter being identified by the ratio of infrared luminosity versus isophotal area, log [(L_FIR_/L_{sun}_)/(D^2^_25_/kpc^2^)]>7.25. (U)LIRGs are found to have the highest averaged R_31_ value. This may be a consequence of particularly vigorous star formation activity, triggered by galaxy interaction and merger events.
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