Discovery of a tidal dwarf galaxy in the Leo Triplet

Abstract

We report discovery of a dwarf galaxy in the Leo Triplet. Analysis of the neutral hydrogen distribution shows that it rotates independently of the tidal tail of NGC 3628, with a radial velocity gradient of 35-40 km s${}^{-1}$ over approximately 13 kpc. The galaxy has a very high neutral gas content, explaining large part of its total dynamic mass - suggesting small dark matter content. As it is located at the tip of the gaseous tail, this strongly suggests its tidal origin. Should it be the case, it would be one of the most confident and closest (to the Milky Way) detections of a tidal dwarf galaxy and, at the same time, a most detached from its parent galaxy ($\approx$140 kpc) object of this type.

6 pages, 4 figures; The Astrophysical Journal, in press

References in corpus (3)

• FIGGS: Faint Irregular Galaxies GMRT Survey - Overview, observations and first results
• Understanding the H2/HI Ratio in Galaxies
• VCC 2062: an old Tidal Dwarf Galaxy in the Virgo Cluster?

Cited by in corpus (5)

• Large-scale structure and galaxy motions in the Leo/Cancer constellations
• A search for extended radio emission from selected compact galaxy groups
• HI mapping of the Leo Triplet: Morphologies and kinematics of tails and bridges
• The pride of lions around Messier 105
• Searching for the magnetised Tidal Dwarf Galaxies in Hickson Compact Groups: HCG 26, 91, and 96