2004/12/02 by Fumiaki Nakata, R. G. Bower, Richard G. Bower +2 · 21 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Brightest cluster galaxy #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Galaxy group #Peculiar galaxy #Physics #Redshift #Redshift survey #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2005.08673.x
published in Monthly Notices of the Royal Astronomical Society 357(2), 679-686 (Oxford University Press) · 8 pages, 7 figures, accepted for publication in MNRAS
arxiv created 2004/12/02 · openalex publication_date 2005/02/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the evolution of the star formation rate in cluster galaxies. We complement data from the Canadian Network for Observational Cosmology 1 (CNOC1) cluster survey (0.15 < z < 0.6) with measurements from galaxy clusters in the Two-degree Field (2dF) galaxy redshift survey (0.05 < z < 0.1) and measurements from recently published work on higher-redshift clusters, up to almost z= 1. We focus our attention on galaxies in the cluster core, i.e. galaxies with r < 0.7h−170 Mpc. Averaging over clusters in redshift bins, we find that the fraction of galaxies with strong [Oii] emission is ≲20 per cent in cluster cores, and the fraction evolves little with redshift. In contrast, field galaxies from the survey show a very strong increase over the same redshift range. It thus appears that the environment in the cores of rich clusters is hostile to star formation at all the redshifts studied. We compare this result with the evolution of the colours of galaxies in cluster cores, first reported by Butcher and Oemler. Using the same galaxies for our analysis of the [Oii] emission, we confirm that the fraction of blue galaxies, which are defined as galaxies 0.2 mag bluer in the rest-frame B–V than the red sequence of each cluster, increases strongly with redshift. Because the colours of galaxies retain a memory of their recent star formation history, while emission from the [Oii] line does not, we suggest that these two results can best be reconciled if the rate at which the clusters are being assembled is higher in the past, and the galaxies from which it is being assembled are typically bluer.