Tidal Dwarf Galaxies around a Post-Merger Galaxy, NGC 4922

  • Sheen, Yun-Kyeong (Department of Astronomy, Yonsei University) ;
  • Jeong, Hyun-Jin (Department of Astronomy, Yonsei University) ;
  • Yi, Suk-Young K (Department of Astronomy, Yonsei University) ;
  • Ferreras, Ignacio (Mullard Space Science Laboratory, University College London) ;
  • Lotz, Jennifer M. (National Optical Astronomy Observatory) ;
  • Olsen, Knut A.G. (National Optical Astronomy Observatory) ;
  • Dickinson, Mark (National Optical Astronomy Observatory) ;
  • Barnes, Sydney (Lowell Observatory) ;
  • Lee, Young-Wook (Department of Astronomy, Yonsei University) ;
  • Park, Jang-Hyun (Korea Astronomy and Space Science Institute) ;
  • Ree, Chang-H. (Korea Astronomy and Space Science Institute)
  • Published : 2009.10.15

Abstract

One possible channel for the formation of dwarf galaxies involves birth in the tidal tails of interacting galaxies. We report the detection of a bright UV tidal tail and several young tidal dwarf galaxy candidates in the post-merger galaxy NGC 4922 in the Coma cluster. Based on a two-component population model (combining young and old stellar populations), we find that its light predominantly comes from young stars (a few Myr old). The Galaxy Evolution Explorer (GALEX) ultraviolet data played a critical role in the parameter (age and mass) estimation. Our stellar mass estimates of the tidal dwarf galaxy candidates are ~10^{6-7} M_sun, typical for dwarf galaxies.

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