KUG 0200-096: Dwarf Antennae Hosting a Tidal Dwarf Galaxy

Abstract

We study a gas-rich merging dwarf system KUG 0200-096. Deep optical imaging reveals an optically faint tail with a length of 20 kpc, giving a visual impression of tidal antenna similar to NGC 4038/39. The interacting dwarf galaxies have B -band absolute magnitudes of −18.06 and −16.63 mag. We identify a young stellar clump with a stellar mass of 2 × 10 7 M ⊙ at the tip of the antenna, possibly a tidal dwarf galaxy (TDG). The putative TDG candidate is quite blue with a g  −  r color index of −0.07 mag, whereas the interacting dwarf galaxies have g  −  r color indices 0.29 and 0.19 mag. The TDG is currently forming stars at the rate of 0.02 M ⊙ yr −1 . We obtained H i 21 cm line data of KUG 0200-096 using the Giant Metrewave Radio Telescope to get a more detailed view of neutral hydrogen (H i ) emission in interacting dwarf galaxies and its TDG. Evidence of a merger between the dwarf galaxy pair is also present in H i kinematics and morphology where we find the H i contents of the interacting pair is disturbed, forming an extended tail toward the TDG. The H i velocity field shows a strong gradient along the H i tidal tail extension. We present a comparative study between the Antennae galaxy, NGC 4038/39, and KUG 0200-096 in both optical and H i gas properties and discuss the possible origin of the KUG 0200-096 TDG.