Extending the Search for Counterrotating Gas and Stars in Galaxies: A Study of Late-Type Dwarfs

Abstract

In a previous study on gas-stellar counterrotation for a large sample of E/S0 and spiral galaxies (Kannappan & Fabricant 2001), two dwarf irregular galaxies were included, of which one was tentatively identified as a counterrotator. Here we extend the search for counterrotation to include 10 more irregular/spiral dwarf galaxies. We find that all systems with well defined gas and stellar rotation show kinematics consistent with co-rotation. However, we see evidence of decoupled gas and stellar kinematics in >~ 50% of the sample, possibly reflecting minor interactions too small to create large-scale gas-stellar counterrotation.

2 pages including 2 figures; to appear in The Ninth Texas Mexico Conference on Astrophysics, RevMexAA, Serie de Conferencias, ed. Silvia Torres-Peimbert and G. MacAlpine