Morphology of Dust Lanes in Bars

Abstract

Given that dust and molecular gas tend to concentrate at the locations of either shocks or orbit crowding, the study of the dust morphology of barred spirals can give insight into the kinematics of the galaxies. In order to do this, we present a sample of barred galaxies for which we have obtained near infrared and optical photometry and BIMA interferometer observations of CO emission. We obtain the dust extinction and relative scale height of the dust and stars using a radiative transfer model to interpret the photometry. We find that the scale height of the stars compared to the dust is generally larger in the central regions compared to further out in the bar dust lanes. The morphology of the dust extinction regions closely resembles the distribution of CO emission. An analysis of a larger sample of galaxies with IR data indicates that dust column densities appear larger in the nuclear regions than in the bar dust lanes. The sample also shows that the distribution of dust is not symmetrical along the bar with one side of the bar usually having a larger column density of dust than the other side.