We use a 2-dimensional high-resolution density field of galaxies of the Las Campanas Redshift Survey (LCRS) with a smoothing length 0.8 h-1 Mpc to extract clusters and groups of galaxies, and a low-resolution field with a smoothing length 10 h-1 Mpc to find superclusters of galaxies. We study the properties of these density field (DF) clusters and superclusters, and compare the properties of the DF-clusters and superclusters with those of Abell clusters and superclusters and LCRS groups. We show that among the cluster samples studied the DF-cluster sample best describes the large-scale distribution of matter and the fine structure of superclusters. We calculate the DF-cluster luminosity function and find that clusters in high-density environments are about ten times more luminous than those in low-density environments. We show that the DF-superclusters that contain Abell clusters are richer and more luminous than the DF-superclusters without Abell clusters. The distribution of DF-clusters and superclusters shows the hierarchy of systems in the universe.
Astronomy and Astrophysics
- Pub Date:
- October 2003
- cosmology: observations;
- cosmology: large-scale structure of the Universe;
- galaxies: clusters: general;
- 19 pages LaTeX text, 15 PostScript Figures, submitted to Astronomy and Astrophysics