Tidal Dwarf Galaxies in the Interacting System NGC 2992/2993

We present multi-wavelength results and numerical simulations of the interacting system NGC 2992/2992 (Arp 245). This pair is composed of two colliding spiral galaxies out of which emanate long stellar tails and a bridge. H II regions are observed at the end of one of the stellar tails at the location of an object classified as a tidal dwarf galaxy. Our spectacular VLA HI map reveals a huge intergalactic ring associated with NGC 2993 and a long tidal tail escaping from NGC 2992 coinciding with the optical one, with at its tip a massive clump that hosts most of the atomic gas in the system. The latter is associated with the star-forming tidal dwarf. Unlike the tail, most of the HI ring has no stellar counterpart.