VLA HI and OVRO CO Interferometry of a Tidal Dwarf Galaxy

Abstract

We present high resolution interferometric observations of the cool atomic and cold molecular ISM of the TDG candidate Arp 245N, an object resembling a dwarf galaxy in the northern tidal tail of the interacting system NGC 2992/3. We observed the HI line with the NRAO VLA and the CO(1-->0) transition with the OVRO millimeter interferometer at 5''-6'' angular resolution (750 pc linear resolution). These datacubes offer the required spatial and velocity resolution to determine whether the mass concentration near the tip of the tail is a genuine feature, and hence a good TDG candidate, or an artefact caused by a fortuitous alignment of our line of sight with the direction of the tail. A preliminary analysis seems to confirm that Arp 245N is a self-gravitating entity.