The Bulletin of The Korean Astronomical Society (천문학회보)

The Korean Astronomical Society (한국천문학회)
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Measuring the Environmental Quenching Timescales of Galaxy Clusters in the COSMOS field

  • Ko, Eunhee (Astronomy program, Dept. of Physics & Astronomy, Seoul National University) ;
  • Im, Myungshin (Astronomy program, Dept. of Physics & Astronomy, Seoul National University) ;
  • Lee, Seong-Kook (Astronomy program, Dept. of Physics & Astronomy, Seoul National University) ;
  • Paek, Insu (Astronomy program, Dept. of Physics & Astronomy, Seoul National University) ;
  • Park, Bomi (Astronomy program, Dept. of Physics & Astronomy, Seoul National University)
  • Published : 2021.10.13
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Abstract

Using 74 galaxy clusters in the COSMOS field at 0.1 < z < 1.2, we calculate the environmental quenching timescale, defined as the time required after a galaxy is accreted by a cluster for it to stop star formation. Cluster candidates are selected as the overdensities with the surface number density exceeding the 4-σ. With the "delayed-then-rapid" quenching model, we can successfully reproduce the separation of the galaxies(star-forming, intermediate, and quiescent) on the NUV-R - R-J color plane comparing with the BC03 evolutionary track. With the mass growth rate of halo mass and the ratio of categorized galaxies, we can constratin the environmental quenching timescale ~ 2Gyr at z ~ 1. We will present the result as a function of redshift and compare them with dynamical timescale and gas depletion timescale.

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