1999/12/16 by Christopher J. Miller, Adrian L. Melott, Miller, Christopher J. +4
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9912362
openalex publication_date 1999/12/16 · arxiv created 1999/12/19 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We examine the relationship between the total X-ray and optical luminosities\nof groups and clusters of galaxies taken from various samples in the\nliterature. The clusters and groups were drawn from four different catalogs:\n(1) the Abell/ACO catalog, (2) the Edinburgh-Durham Cluster Catalog, (3) the\nRASS Bright Cluster Sample, and (4) galaxy groups selected from the CfA\nredshift survey. These catalogs represent a significant cross-section of\ncluster selection tchniques as well as a wide range in mass scale and can be\nconsidered statistically independent. We have calculated new cluster X-ray and\noptical luminosities if not available in the literature. Based on 126 systems,\nour analysis shows that the total optical luminosity of a cluster is directly\nproportional to the total X-ray luminosity over a wide mass range and across\nall four cluster samples studied herein. We also show that total cluster\noptical luminosity is a good indicator of cluster virial mass, but richness is\nnot. Our results suggest that (1) the selection method of galaxy clusters may\nnot be crucial, providing wider latitude in assembling catalogs, (2) the\nluminosity per baryon does not vary systematically between systems ranging from\ngroups to very rich clusters. We propose that future optical catalogs of\nclusters use the total optical luminosity of a cluster, instead of galaxy\nrichness, as luminosity appears to be a better measure of cluster mass and can\nbe directly related to X-ray catalogs of clusters. This will also facilitate\nthe first direct comparison between the growing number of X-ray and optical\ncatalogs.\n