Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
<mark>Journal publication date</mark> | 11/03/2008 |
---|---|
<mark>Journal</mark> | Monthly Notices of the Royal Astronomical Society |
Issue number | 4 |
Volume | 384 |
Number of pages | 9 |
Pages (from-to) | 1502-1510 |
Publication Status | Published |
Early online date | 4/02/08 |
<mark>Original language</mark> | English |
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 L X > 10 44 erg 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 L X > 5 × 10 44 erg 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.