The Bulletin of The Korean Astronomical Society (천문학회보)

The Korean Astronomical Society (한국천문학회)
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Ultraviolet Properties of Dwarf Galaxies in Fornax Cluster and Ursa Major Group

  • Lee, Young-Dae (Department of Astronomy and Space Science, Chungnam National University) ;
  • Rey, Soo-Chang (Department of Astronomy and Space Science, Chungnam National University) ;
  • Pak, Mi-Na (Department of Astronomy and Space Science, Chungnam National University) ;
  • Kim, Suk (Department of Astronomy and Space Science, Chungnam National University) ;
  • Sung, Eon-Chang (Korea Astronomy and Space Science Institute) ;
  • Yi, Won-Hyeong (Department of Astronomy and Space Science, Chungnam National University) ;
  • Chung, Ji-Won (Department of Astronomy and Space Science, Chungnam National University)
  • Published : 2010.10.06
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Abstract

We present ultraviolet (UV) photometric properties of dwarf galaxies in Fornax cluster and Ursa Major group in comparison with Virgo cluster using GALEX data. We construct UV color-magnitude relations (CMRs) of dwarf galaxies matching with available optical photometry and SDSS data. Majority of dwarf galaxies in Fornax cluster show sequence in UV CMRs consistent with that of dwarf elliptical (dEs) in Virgo cluster indicating similar age and metallicity properties of dEs in two clusters. The dS0 sequence in Fornax cluster is not distinct as much as that in Virgo cluster. Dwarf galaxies in outer region of the Fornax cluster show more bluer UV colors with a wide scatter in CMRs, which indicates recent star formation activity. We show that the UV colors of dwarf galaxies are related with the distribution and strength of the X-ray emission in the cluster. In contrast to the Fornax cluster, most dwarf galaxies in Ursa Major group are located in the blue cloud showing recent or on-going star formation, and few galaxies show characteristics of dEs. We discuss relationship between UV properties of dwarf galaxies and different environment of cluster.

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