Nearby galaxies. III. Gas–to–dust ratio in the interstellar medium of spiral and dwarf irregular galaxies

The gas-to-dust ratio in the interstellar medium of nearby spiral systems and dwarf irregular galaxies has been obtained by using mainly the compiled data by Schmidt and Boller (1992a). The gas-to-dust ratio of dwarf irregulars is larger by about one order of magnitude than for spiral galaxies, on the average. A relation between the gas-to-dust ratio and the metallicity, represented by the abundance of oxygen, has been detected.