LoCuSS: Pre-processing in galaxy groups falling into massive galaxy clusters at z = 0.2

M. Bianconi, G. P. Smith, C. P. Haines, S. L. McGee, A. Finoguenov, E. Egami

Research output: Contribution to journalArticlepeer-review

34 Scopus citations

Abstract

We report direct evidence of pre-processing of the galaxies residing in galaxy groups falling into galaxy clusters drawn from the Local Cluster Substructure Survey (LoCuSS). 34 groups have been identified via theirX-ray emission in the infall regions of 23 massive (〈M200〉 = 1015M⊙) clusters at 0.15 < z < 0.3. Highly complete spectroscopic coverage combined with 24 μm imaging from Spitzer allows us to make a consistent and robust selection of cluster and group members including star-forming galaxies down to a stellar mass limit of M∗ = 2 × 1010M⊙. The fraction fSF of star-forming galaxies in infalling groups is lower and with a flatter trend with respect to clustercentric radius when compared to the rest of the cluster galaxy population. At R ≈ 1.3 r200, the fraction of star-forming galaxies in infalling groups is half that in the cluster galaxy population. This is direct evidence that star-formation quenching is effective in galaxies already prior to them settling in the cluster potential, and that groups are favourable locations for this process.

Original languageEnglish (US)
Pages (from-to)L79-L83
JournalMonthly Notices of the Royal Astronomical Society: Letters
Volume473
Issue number1
DOIs
StatePublished - Jan 2018

Keywords

  • Galaxies: clusters: general
  • Galaxies: evolution
  • Galaxies: groups: general
  • Galaxies: star formation

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint

Dive into the research topics of 'LoCuSS: Pre-processing in galaxy groups falling into massive galaxy clusters at z = 0.2'. Together they form a unique fingerprint.

Cite this