Candidate Tidal Dwarf Galaxies in the Compact Group CG J1720−67.8

This is the second part of a detailed study of the ultracompact group CGJ1720-67.8: in the first part we have focused the attention on the three maingalaxies of the group and we have identified a number of candidate tidal dwarfgalaxies (TDGs). Here we concentrate on these candidate TDGs. Absolutephotometry of these objects in BVRJHKs bands confirms their relatively bluecolors, as we already expected from the inspection of optical and near-infraredcolor maps and from the presence of emission-lines in the optical spectra. Thephysical conditions in such candidate TDGs are investigated through theapplication of photoionization models, while the optical colors are comparedwith grids of spectrophotometric evolutionary synthesis models from theliterature. Although from our data self-gravitation cannot be proved for theseobjects, their general properties are consistent with those of other TDGcandidates. Additionally we present the photometry of a few ``knots'' detectedin the immediate surroundings of CG J1720-67.8 and consider the possibilitythat these objects might belong to a dwarf population associated with thecompact group.Comment: Accepted for publication in the Astrophysical Journa