Star‐forming Objects in the Tidal Tails of Compact Groups

Abstract

A search for star-forming objects belonging to tidal tails has been carried out in a sample of deep Ha images of 16 compact groups of galaxies. A total of 36 objects with Ha luminosities greater than 1038 ergs s~1 has been detected in Ðve groups. The fraction of the total Ha luminosity of their respective parent galaxies shown by the tidal objects is always below 5% except for the tidal features of Hickson compact group 95, whose Ha luminosity amounts to 65% of the total luminosity. Out of these 36 objects, nine star-forming tidal dwarf galaxy candidates Ðnally have been identiÐed on the basis of their projected distances to the nuclei of the parent galaxies and their total Ha luminosities. Overall, the observed properties of the candidates resemble those previously reported for the so-called tidal dwarf galaxies.