2007/12/04 by J. P. Stott, A. C. Edge, G. P. Smith +2 · 7 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Scientific Research and Discoveries #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2007.12807.x
published as MNRAS, Volume 384, Issue 4, pp. 1502-1510 (2008) · 9 figures, MNRAS in press
arxiv created 2007/12/04 · openalex publication_date 2008/01/31 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We investigate the near-infrared evolution of brightest cluster galaxies (BCGs) from a sample of rich galaxy clusters since z∼ 1. By employing an X-ray selection of LX > 1044erg s−1, we limit environmental effects by selecting BCGs in comparably high-density regions. We find a positive relationship between X-ray and near-infrared luminosity for BCGs in clusters with LX > 5 × 1044erg s−1. Applying a correction for this relation, we reduce the scatter in the BCG absolute magnitude by a factor of 30 per cent. The near-infrared J−K colour evolution demonstrates that the stellar population in BCGs has been in place since at least z= 2, and that we expect a shorter period of star formation than that predicted by current hierarchical merger models. We also confirm that there is a relationship between ‘blue’J−K colour and the presence of BCG emission lines associated with star formation in cooling flows.