Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
<mark>Journal publication date</mark> | 11/04/2010 |
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<mark>Journal</mark> | Monthly Notices of the Royal Astronomical Society |
Issue number | 3 |
Volume | 403 |
Number of pages | 9 |
Pages (from-to) | 1274-1282 |
Publication Status | Published |
Early online date | 1/04/10 |
<mark>Original language</mark> | English |
We study the ratio of luminous to faint red-sequence galaxies in both optically and X-ray selected galaxy clusters in the poorly studied redshift range 0.05 ≤ z <0.19. The X-ray-selected sample consists of 112 clusters based on the ROSAT All-Sky Survey, while the optical sample consists of 266 clusters from the Sloan Digital Sky Survey. Our results are consistent with the presence of a trend in luminous-to-faint ratio with redshift, confirming that downsizing is continuous from high to low redshift.After correcting for the variations with redshift using a partial Spearman analysis, we find no significant relationship between luminous-to-faint ratio and X-ray luminosity of the host cluster sample, in contrast to recent suggestions. Finally, we investigate the stacked colour-magnitude relations of these samples, finding no significant differences between the slopes for optically and X-ray selected clusters. The colour-magnitude slopes are consistent with the values obtained in similar studies, but not with predictions of theoretical models.