Clusters and superclusters in the Las Campanas redshift survey

¹ Tartu Observatory, 61602 Tõravere, Estonia
² Fermi National Accelerator Laboratory, MS 127, PO Box 500, Batavia, IL 60510, USA
³ Astrophysical Institute Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany
⁴ Tuorla Observatory, Väisäläntie 20, Piikkiö, Finland
⁵ Dept. of Astronomy, New Mexico State University, Las Cruces, NM 88003-8001, USA

Corresponding author: J. Einasto, einasto@aai.ee

Received: 6 May 2003
Accepted: 17 July 2003

Abstract

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.