Medium Resolution Spectroscopy of Red Giant Stars in Omega Centauri

  • Jung, Jae In (Department of Science Education, Ewha Womans University) ;
  • An, Deokkeun (Department of Science Education, Ewha Womans University) ;
  • Lee, Young Sun (Department of Astronomy & Space Science, Chungnam National University) ;
  • Rey, Soo-Chang (Department of Astronomy & Space Science, Chungnam National University) ;
  • Lee, Jae-Woo (Department of Astronomy and Space Science, Sejong University) ;
  • Lee, Young-Wook (Center for Galaxy Evolution Research, Yonsei University) ;
  • Rhee, Jaehyon
  • Published : 2016.10.12

Abstract

We present chemical abundances for about 800 red giant stars in Omega Centauri, based on medium-resolution spectra obtained using Hydra multi-fiber spectrograph at the CTIO 4-m telescope. Our sample covers 14.2 < V < 15.0, and is almost unbiased against colors (and therefore metallicity). The metallicity distribution function (MDF) constructed from our data has an overall shape and local peaks that approximately match those for brighter giant stars in Johnson et al.. We also find that more metal-rich cluster members are more concentrated in the cluster center, which is consistent with previous studies. On the other hand, we find no clear evidence for such a spatial dependence with respect to alpha elemental abundance ([${\alpha}/Fe$]).

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