Radial density and temperature profiles of the intracluster gas constructed jointly from the X-ray surface brightness measurement and the universal density profile

Abstract

In this paper we have made an attempt to derive the radial profiles of density and temperature of intracluster gas based on the two well-established facts at present: the X-ray observed surface brightness of clusters described by the standard beta model and the (NFW) universal density profile as the underlying dark matter distribution. We have numerically solved the hydrostatic equation by demanding that the volumed-averaged baryon fraction of a cluster should asymptotically approach the universal value at its viral radius. We have shown that the radial temperature variation derived from these constraints differs significantly from the conventional polytropic equation of state: The gas temperature profile may show a dramatic increase or decrease with outward radius, depending sensitively on the beta parameter. A large beta value (typically greater than 0.8) is required in order to ensure that the X-ray temperature makes a drop at the virial radius. This indicates that either the NFW profile is inappropriate to apply for the overall dark matter distribution of clusters or other non-gravitational heating processes may play an important role in the dynamical evolution of clusters.

26 pages, 4 figures, accepted for publication in ApJ

References in corpus (8)

• The entropy and energy of intergalactic gas in galaxy clusters
• Collisional dark matter and the structure of dark halos
• Heating of Intergalactic Gas and Cluster Scaling Relations
• Radial Temperature Profiles of 11 Clusters of Galaxies Observed With BeppoSAX
• A combined analysis of cluster mass estimates from strong lensing, X-ray measurement and the universal density profile
• Properties of the double beta model for intracluster gas
• Correlation Between the Halo Concentration (c) and the Virial Mass (Mvir) Determined from X-ray Clusters
• On the radial density profile of intracluster gas tracing the isothermal dark halo with a finite core

Cited by in corpus (4)

• Nonthermal Particles and Radiation Produced by Cluster Merger Shocks
• Probing the Core Structure of Dark Halos with Tangential and Radial Arc Statistics
• Morphology of low-redshift compact galaxy clusters I. Shapes and radial profiles
• Reconstruction of Gas Temperature and Density Profiles of the Galaxy Cluster RX J1347.5-1145