Internal cluster structure

• Verfasst von: Bartelmann, Matthias [VerfasserIn]
• Verfasst von: Schmidt, Robert W. [VerfasserIn]
• Titel: Internal cluster structure
• Verf.angabe: Matthias Bartelmann, Marceau Limousin, Massimo Meneghetti, Robert Schmidt
• Fussnoten: Gesehen am 21.09.2017
• Titel Quelle: Enthalten in: De.arxiv.org
• Jahr Quelle: 2013
• Band/Heft Quelle: (2013) Artikel-Nummer 1303.3285, 29 Seiten
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 156368845X

Abstract

The core structure of galaxy clusters is fundamentally important. Even though self-gravitating systems have no stable equilibrium state due to their negative heat capacity, numerical simulations find density profiles which are universal in the sense that they are fairly flat within a scale radius and gradually steepen farther outward, asymptotically approaching a logarithmic slope of $\approx-3$ near the virial radius. We argue that the reason for the formation of this profile is not satisfactorily understood. The ratio between the virial radius and the scale radius, the so-called concentration, is found in simulations to be closely related to the mass and the redshift and low for cluster-sized haloes, but observed to be substantially higher at least in a subset of observed clusters. Haloes formed from cold dark matter should furthermore be richly substructured. We review theoretical and observational aspects of cluster cores here, discuss modifications by baryonic physics and observables that can provide better insight into the internal structure of clusters.