相关论文: Modified-Entropy Models for the Intracluster Mediu…

Studies of the X-ray surface brightness profiles of clusters, coupled with theoretical considerations, suggest that the breaking of self-similarity in the hot gas results from an `entropy floor', established by some heating process, which…

[Abridged] The entropy distribution of the intracluster gas reflects both accretion history of the gas and processes of feedback which provide a further non-gravitational energy besides the potential one. In this work, we study the profiles…

Clusters of galaxies are thought to contain about ten times as much dark matter as baryonic matter. The dark component therefore dominates the gravitational potential of the cluster, and the baryons confined by this potential radiate X-rays…

We use hydrodynamical simulations of galaxy clusters and groups to study the effect of pre-heating on the entropy structure of the ICM. Our simulations account for non-gravitational heating of the gas either by imposing a minimum entropy…

The radial entropy profile of the hot gas in clusters of galaxies tends to follow a power law in radius outside of the cluster core. Here we present a simple formula giving both the normalization and slope for the power-law entropy profiles…

We construct a family of simple analytical models of galaxy clusters at the present epoch and compare its predictions with observational data. We explore two processes that break the self-similarity of galaxy clusters: systematic variation…

We propose a novel component to the understanding of the temperature structure of galaxy clusters which does not rely on any heating or cooling mechanism. The new ingredient is the use of non-extensive thermo-statistics which is based on…

Galaxy groups differ from clusters primarily by way of their lower masses, M~10^14 M_sun vs. M~10^15 M_sun. We discuss how mass affects the thermal state of the intracluster or the intragroup medium, specifically as to their entropy levels…

We present a new model for the X-ray properties of the intracluster medium that explicitly includes heating of the gas by the energy released during the evolution of cluster galaxies. We calculate the evolution of clusters by combining the…

Turbulent heating may play an important role in galaxy-cluster plasmas, but if turbulent heating is to balance radiative cooling in a quasi-steady state, some mechanism must set the turbulent velocity to the required value. This paper…

X-ray observations indicate that non-gravitational processes play a key role in determining the distribution of the diffuse, X-ray emitting gas in clusters of galaxies (ICM). The effect of non-gravitational processes is imprinted in the ICM…

Influence of surrounding matter on the properties of clusters is considered by an approach combining the methods of statistical and quantum mechanics. A cluster is treated as a bound N-particle system and surrounding matter as thermostat.…

We report the results of our study of fractional entropy enhancement in the intra-cluster medium (ICM) of the clusters from the representative XMM-Newton cluster structure survey (REXCESS). We compare the observed entropy profile of these…

I investigate an analytical model of galaxy clusters based on the assumption that the intracluster medium plasma is polytropic and is in hydrostatic equilibrium. The Einasto profile is adopted as a model for the spatial-density distribution…

Recent observations of entropy of intracluster medium (ICM) at high redshift are not consistent with a redshift independent entropy floor. In order to interpret these observations, we study models in which the entropy of ICM is enhanced at…

(Abridged) We revisit the scaling relationships between the dark matter mass and observed X-ray luminosity and temperature of galaxy clusters and groups in the local Universe. Specifically, we compare recent observations with analytic…

Many processes within galaxy clusters, such as those believed to govern the onset of thermally unstable cooling and AGN feedback, are dependent upon local dynamical timescales. However, accurately mapping the mass distribution within…

Several physical processes and formation events are expected in cluster outskirts, a vast region up to now essentially not covered by observations. The recent Suzaku (X-ray) and Planck (Sunayev-Zeldovich effect) observations out to the…

We use gas dynamic simulations to explore the effects of galactic winds on galaxy clusters. Two ensembles of 18 realizations, spanning a decade in temperature, are evolved with and without winds in an underlying biased CDM cosmology.…

Aims. We aim to provide constraints on evolutionary scenarios in clusters. One of our main goals is to understand whether, as claimed by some, the cool core/non-cool core division is established once and for all during the early history of…