KUG 0200-096: Dwarf antennae hosting a tidal dwarf galaxy

TL;DR

This study investigates a gas-rich merging dwarf galaxy system, revealing a tidal tail and a potential tidal dwarf galaxy formed at its tip, supported by optical and HI observations, and compares it to the Antennae galaxy.

Contribution

It provides the first detailed optical and HI analysis of KUG 0200-096, identifying a candidate tidal dwarf galaxy and comparing its properties to a well-known merger, expanding understanding of dwarf galaxy interactions.

Findings

Discovery of a 20 kpc tidal tail in KUG 0200-096.

Identification of a young, blue stellar clump as a potential TDG.

Evidence of disturbed HI morphology and velocity gradient indicating merger activity.

Abstract

We study a gas rich merging dwarf system KUG 0200-096. Deep optical image 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 -18.06 and -16.63 mag. We identify a young stellar clump of stellar mass of 2$\times$10$^{7}$ M$_{\sun}$ at the tip of the antenna, possibly a Tidal Dwarf Galaxy (TDG). The putative TDG candidate is quite blue with $g-r$ 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 star at the rate of 0.02 M$_{\sun}$/yr. We obtained HI 21 cm line data of KUG 0200-096 using the GMRT to get a more detailed view of neutral hydrogen (HI) emission in interacting dwarf galaxies and its TDG. Evidence of merger between the dwarf galaxy pair is also presence in HI kinematics and morphology where we find the HI contents of interacting pair is disturbed, forming a extended tail toward the TDG. The HI velocity field shows strong gradient along the HI tidal tail extension. We present a comparative study between the Antennae galaxy, NGC 4038/39, and KUG 0200-096 in both optical and HI gas properties and discuss possible origin of KUG 0200-096 TDG.