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The structure of galaxy clusters in various cosmologies |
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| Authors: | Peter A Thomas Jörg M Colberg Hugh M P Couchman George P Efstathiou Carlos S Frenk Adrian R Jenkins Alistair H Nelson Roger M Hutchings John A Peacock Frazer R Pearce & Simon D M White |
| Institution: | Astronomy Centre, University of Sussex, Falmer, Brighton BN1 9QH,;Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Strasse 1, 85740, Garching bei München, Germany,;Department of Physics &Astronomy, University of Western Ontario, London, Ontario, N6A 3K7, Canada,;Department of Astrophysics, Nuclear &Astrophysics Laboratory, Keble Road, Oxford OX1 3RH,;Department of Physics, South Road, Durham DH1 3LE,;Department of Physics, College of Cardiff, PO Box 913, Cardiff CF4 3TH,;Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ |
| Abstract: | We investigate the internal structure of clusters of galaxies in high-resolution N -body simulations of four different cosmologies. There is a higher proportion of disordered clusters in critical-density than in low-density universes, although the structure of relaxed clusters is very similar in each case. Crude measures of substructure, such as the shift in the position of the centre-of-mass as the density threshold is varied, can distinguish the two in a sample of just 20 or so clusters; it is harder to differentiate between clusters in open and flat models with the same density parameter. Most clusters are in a quasi-steady state within the virial radius and are well-described by the density profile of Navarro, Frenk & White. |
| Keywords: | galaxies: clusters: general cosmology: miscellaneous |