Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-11-23
Mon.Not.Roy.Astron.Soc.366:645-666,2006
Astronomy and Astrophysics
Astrophysics
25 pages, 16 figures. Accepted for publication in MNRAS
Scientific paper
10.1111/j.1365-2966.2005.09892.x
[abridged] We present the analysis of the spectroscopic and photometric catalogues of 11 X-ray luminous clusters at z=0.07-0.16 from the Las Campanas / Anglo-Australian Telescope Rich Cluster Survey. Our spectroscopic dataset consists of over 1600 galaxy cluster members, of which two thirds are outside r_200. We assign cluster membership using a detailed mass model and expand on our previous work on the cluster colour-magnitude relation where membership was inferred statistically. We confirm that the modal colours of galaxies on the colour magnitude relation become progressively bluer with increasing radius and decreasing local galaxy density. Interpreted as an age effect, we hypothesize that these trends in galaxy colour should be reflected in mean Hdelta equivalent width. We confirm that passive galaxies in the cluster increase in Hdelta line strength as dHdelta / d r_p = 0.35 +/- 0.06. A variation of star formation rate, as measured by [OII], with increasing local density of the environment is discernible and is shown to be in broad agreement with previous studies from 2dFGRS and SDSS. We find that clusters at z~0.1 are less active than their higher redshift analogues. We also investigate unusual populations of blue and very red nonstarforming galaxies and we suggest that the former are likely to be the progenitors of galaxies which will lie on the colour-magnitude relation, while the colours of the latter possibly reflect dust reddening. The cluster galaxies at large radii consist of both backsplash ones and those that are infalling to the cluster for the first time. We make a comparison to the field population at z~0.1 and examine broad differences between the two populations. Individually, the clusters show significant variation in their galaxy populations which reflects their recent infall histories.
Couch Warrick J.
Edge Alastair C.
O'Hely Eileen
Pimbblet Kevin A.
Smail Ian
No associations
LandOfFree
The Las Campanas/AAT Rich Cluster Survey III: Spectroscopic Studies of X-ray Bright Galaxy Clusters at z~0.1 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Las Campanas/AAT Rich Cluster Survey III: Spectroscopic Studies of X-ray Bright Galaxy Clusters at z~0.1, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Las Campanas/AAT Rich Cluster Survey III: Spectroscopic Studies of X-ray Bright Galaxy Clusters at z~0.1 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-542524