Investigation of barred galaxies. vi. a comparative statistics of sb and sa galaxies. the cold gas properties

Abstract

The gas properties of barred and unbarred spiral galaxies are compared in two complete samples. It is found that two types of spiral galaxies do not differ from each other in atomic and molecular gas contents. On average there is 6 times more HI than H2 in spiral galaxies and the ratio MH2/MHI decreases from early to late types. The barred and unbarred spirals in general show a similar behaviors of the gas-to-luminosity relationships, but also there are certain differences between them such as correlation of two gas phases (HI and H2)for unbarred galaxies. It is suggested that different behaviors of two types galaxies are due to the higher star forming activity of barred with respect unbarred spirals. The expected values of HI and H2 gas contents have been estimated using blue and far-infrared emission.