相关论文: The Heating of the Intra Cluster Medium
X-ray observations indicate that non-gravitational processes play a key role in the thermodynamics of the Intra Cluster Medium (ICM). The effect of non-gravitational processes is imprinted in the ICM as an entropy minimum, whose effects are…
The thermodynamics of the diffuse, X-ray emitting gas in clusters of galaxies is determined by gravitational processes associated with shock heating, adiabatic compression, and non-gravitational processes such as heating by SNe, stellar…
The thermodynamics of the diffuse, X-ray emitting gas in clusters of galaxies is linked to the entropy level of the intra cluster medium. In particular, models that successfully reproduce the properties of local X-ray clusters and groups…
Non-gravitational feedback affects the nature of the intra-cluster medium (ICM). X-ray cooling of the ICM and in situ energy feedback from AGN's and SNe as well as {\it preheating} of the gas at epochs preceding the formation of clusters…
Recent X-ray observations of clusters of galaxies have shown that the entropy of the intracluster medium (ICM), even at radii as large as half the virial radius, is higher than that expected from gravitational processes alone. This is…
The strong deviation in the properties of X-ray clusters from simple scaling laws highlights the importance of non-gravitational heating and cooling processes in the evolution of proto-cluster gas. We investigate this from two directions:…
We present results from high-resolution Tree+SPH simulations of galaxy clusters and groups, aimed at studying the effect of non-gravitational heating on the entropy of the ICM. We simulate three systems, having emission-weighted temperature…
We investigate the non-gravitational heating of hot gas in clusters of galaxies (intracluster medium; ICM) on the assumption that the gas is heated well before cluster formation ('preheating'). We examine the jet activities of radio…
We analyse the evolution of the Intergalactic Medium (IGM) by means of an extended set of large box size hydrodynamical simulations which include pre-heating. We focus on the properties of the z~2 Lyman-alpha forest and on the population of…
We present results on the heating of the inter-cluster medium (ICM) by gravitational potential energy from in-falling satellites. We calculate the available excess energy of baryons once they are stripped from their satellite and added to…
We point out that two problems of observational cosmology, the facts i) that > 60% of the baryonic content of the universe is not observed at z=0 and ii) that the properties of small clusters do not agree with simple expectations, could be…
X-ray observations of galaxy groups and clusters are inconsistent with the predictions of the simplest hierarchical clustering models, wherein non-baryonic and baryonic components are assembled together under the sole influence of gravity.…
A variety of physical heating mechanisms are combined with radiative cooling to explore, via one dimensional hydrodynamic simulations, the expected thermal properties of the intracluster medium (ICM) in the context of the cooling flow…
We investigate the properties of the intracluster medium (ICM) that forms within N-body/hydrodynamical simulations of galaxy clusters in a \LambdaCDM cosmology. When radiative cooling and a simple model for galactic feedback are included,…
The thermodynamics of the diffuse, X-ray emitting gas in clusters and groups of galaxies are affected by a certain amount of non-gravitational energy input, as indicated by the scaling properties of X-ray halos. Such a view has been…
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…
Recent X-ray observations have highlighted clusters that lack entropy cores. At first glance, these results appear to invalidate the preheated ICM models. We show that a self-consistent preheating model, which factors in the effects of…
Efforts to understand the deviation of the L--T relation from a simple scaling law valid for clusters and groups have triggered a number of interesting studies on the subject. Techniques and approaches differ widely but most works agree on…
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…
(Abridged) The thermal history of the intracluster medium (ICM) is complex. Heat input from cluster mergers, AGN, and galaxy winds offsets and may even halt the cooling of the ICM. Consequently, the processes that set the properties of the…