Properties of the Neutral Interstellar Medium in NGC 185 and NGC 205

Abstract

We describe the properties and kinematics of the neutral gas in the two dwarf elliptical galaxies NGC 185 and NGC 205, companions of M31. The kinematics of the HI suggest that an internal origin for the gas (i.e. stellar mass loss) should be considered, at least in the case of NGC 185. The molecular clouds in these dwarf ellipticals are similar to Galactic giant molecular clouds in many ways. However, the HI column density in the dwarf ellipticals is surprisingly low. A lower interstellar UV field may make it easier to form and retain molecular gas in the dwarf ellipticals than in the solar neighborhood.