MILLIMETER OBSERVATIONS OF A COMPLETE SAMPLE OF IRAS GALAXIES - DUST EMISSION AND ABSORPTION IN SPIRALS

We report on observations performed at 1.25 mm of a southern galaxy sample, selected from the IRAS Point Source Catalog and complete to S-60 = 2 Jy. We detected 18 sources and set significant limits on 10 further objects. We use these data to discuss the spatial distribution of cold dust, the broadband far-IR/millimeter spectra, the overall amount of dust, the gas-to-dust mass ratio, the dust optical depth, and the overall extinction, for such a representative galaxy sample. These results are also supported by a successful comparison with values inferred for the Galaxy. Because of the favorable observational set-up, selection wavelength, and completeness, we believe these data provide an unbiased view of dust properties in spiral galaxies.