H I and CO Emission in Blue Compact Dwarfs: Haro 2 and Haro 4/26

Abstract

We present VLA HI imaging of two actively star-forming dwarf galaxies, Haro 2 and Haro 4, and of the spiral galaxy NGC 3510 (Haro 26), some 22' SW of Haro 4 (8.5kpc). We also present a map of the CO(1-0) distribution of Haro 2 obtained with the OVRO millimeter interferometer and give an upper limit for CO(2-1) from Haro 4. Our results, based on the distribution of the atomic and molecular gas, suggest that both dwarfs are in distinctly different stages of galaxy interaction. The striking kinematics of Haro 2 indicate a recent merger event, whereas the HI distribution and kinematics of Haro 4 and the neighboring spiral NGC 3510 suggest that they are involved in a tidal interaction.