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Substructure Analysis of Selected Low Richness 2dFGRS Clusters of Galaxies

William S. Burgett·Michael M. Vick·David S. Davis·Matthew Colless·Roberto De Propris·Ivan Baldry·Carlton Baugh·Joss Bland-Hawthorn·Terry Bridges·Russell Cannon·Shaun Cole·Chris Collins·Warrick Couch·Nicholas Cross·Gavin Dalton·Simon Driver·George Efstathiou·Richard Ellis·Carlos Frenk·Karl Glazebrook·Edward Hawkins·Carole Jackson·Ofer Lahav·Ian Lewis·Stuart Lumsden·Steve Maddox·Darren Madgwick·Peder Norberg·John A. Peacock·Will Percival·Bruce Peterson·Will Sutherland·Keith Taylor
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Abstract

Complementary one-, two-, and three-dimensional tests for detecting the presence of substructure in clusters of galaxies are applied to recently obtained data from the 2dF Galaxy Redshift Survey. The sample of 25 clusters used in this study includes 16 clusters not previously investigated for substructure. Substructure is detected at or greater than the 99% CL level in at least one test for 21 of the 25 clusters studied here. From the results, it appears that low richness clusters commonly contain subclusters participating in mergers. About half of the clusters have two or more components within 0.5 h^{-1} Mpc of the cluster centroid, and at least three clusters (Abell 1139, Abell 1663, and Abell S333) exhibit velocity-position characteristics consistent with the presence of possible cluster rotation, shear, or infall dynamics. The geometry of certain features is consistent with influence by the host supercluster environments. In general, our results support the hypothesis that low richness clusters relax to structureless equilibrium states on very long dynamical time scales (if at all).

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William S. Burgett, Michael M. Vick, David S. Davis, Matthew Colless, Roberto De Propris, Ivan Baldry, Carlton Baugh, Joss Bland-Hawthorn, Terry Bridges, Russell Cannon, Shaun Cole, Chris Collins, Warrick Couch, Nicholas Cross, Gavin Dalton, Simon Driver, George Efstathiou, Richard Ellis, Carlos Frenk, Karl Glazebrook, Edward Hawkins, Carole Jackson, Ofer Lahav, Ian Lewis, Stuart Lumsden, Steve Maddox, Darren Madgwick, Peder Norberg, John A. Peacock, Will Percival, Bruce Peterson, Will Sutherland, Keith Taylor. 2004-05-03. Substructure Analysis of Selected Low Richness 2dFGRS Clusters of Galaxies. https://doi.org/10.1111/j.1365-2966.2004.07952.x

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