A New Method For Galaxy Cluster Detection I: The Algorithm

dc.creatorGladders, Michael D.
dc.creatorYee, H. K. C.
dc.date2000-04-06
dc.date2000-08-05
dc.date.accessioned2026-07-07T10:47:14Z
dc.date.available2026-07-07T10:47:14Z
dc.descriptionNumerous methods for finding clusters at moderate to high redshifts have been proposed in recent years, at wavelengths ranging from radio to X-rays. In this paper we describe a new method for detecting clusters in two-band optical/near-IR imaging data. The method relies upon the observation that all rich clusters, at all redshifts observed so far, appear to have a red sequence of early-type galaxies. The emerging picture is that all rich clusters contain a core population of passively evolving elliptical galaxies which are coeval and formed at high redshifts. The proposed search method exploits this strong empirical fact by using the red sequence as a direct indicator of overdensity. The fundamental advantage of this approach is that with appropriate filters, cluster elliptical galaxies at a given redshift are redder than all normal galaxies at lower redshifts. A simple color cut thus virtually eliminates all foreground contamination, even at significant redshifts. In this paper, one of a series of two, we describe the underlying assumptions and basic techniques of the method in detail, and contrast the method with those used by other authors. We provide a brief demonstration of the effectiveness of the technique using real redshift data, and from this conclude that the method offers a powerful yet simple way of identify galaxy clusters. We find that the method can reliably detect structures to masses as small as groups with velocity dispersions of only ~300 km/sec, with redshifts for all detected structures estimated to an accuracy of ~10%.
dc.descriptionTo appear in November AJ, 22 pages, including 10 embedded figures, two-column preprint using aas2pp4 style file. For information on the associated 100 square degree, z~1 cluster survey, see http://www.astro.utoronto.ca/~gladders/RCS/
dc.identifierhttps://arxiv.org/abs/astro-ph/0004092
dc.identifierhttp://arxiv.org/abs/astro-ph/0004092
dc.identifierAstron.J.120:2148,2000
dc.identifierdoi:10.1086/301557
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/183464
dc.subjectAstrophysics
dc.titleA New Method For Galaxy Cluster Detection I: The Algorithm
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