Star-formation Properties of High-redshift (z~1) Galaxy Clusters Connected to the Large-scale Structure

  • Lee, Seong-Kook (Center for the Exploration of the Origin of the Universe, Department of Physics and Astronomy, Seoul National University) ;
  • Im, Myungshin (Center for the Exploration of the Origin of the Universe, Department of Physics and Astronomy, Seoul National University) ;
  • Hyun, Minhee (Center for the Exploration of the Origin of the Universe, Department of Physics and Astronomy, Seoul National University) ;
  • Park, Bomi (Department of Astronomy and Space Science, Kyung Hee University) ;
  • Kim, Jae-woo (Korea Astronomy and Space Science Institute) ;
  • Kim, Dohyung (Center for the Exploration of the Origin of the Universe, Department of Physics and Astronomy, Seoul National University) ;
  • Kim, Yongjung (Center for the Exploration of the Origin of the Universe, Department of Physics and Astronomy, Seoul National University)
  • Published : 2017.10.10

Abstract

At local, majority of galaxies in the dense environment, such as galaxy cluster, are red and quiescent with little star-formation (SF) activity. However, a different picture emerges as we go to high redshift: (1) there exist non-negligible fraction of galaxies still forming stars actively even in dense environment, and (2) there is a significant cluster-by-cluster variation in the SF properties, such as quiescent galaxy fraction. In this presentation, we show the results of our study about the variation of quiescent galaxy fraction among high-redshift (z~1) galaxy clusters, based on the multi-object spectroscopic (MOS) observation with IMACS on the Magellan telescope. Our main result is that galaxy clusters which are connected with significant large-scale structure (LSS), well beyond the cluster scale, are more active in their SF activity, i.e., the quiescent galaxy fraction for these clusters is lower compared to the clusters which are detached from LSS.

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