相关论文: Clusters of galaxies: beyond the thermal view
Observations of clusters of galaxies suggest that they contain significantly fewer baryons (gas plus stars) than the cosmic baryon fraction. This `missing baryon' puzzle is especially surprising for the most massive clusters which are…
The detailed velocity structure of the diffuse X-ray emitting intra-cluster medium (ICM) remains one of the last missing key ingredients in understanding the microphysical properties of these hot baryons and constraining our models of the…
About half of the expected total baryon budget in the local Universe is `missing'. Hydrodynamical simulations suggest that most of the missing baryons are located in a mildly overdense, warm-hot intergalactic medium (WHIM), which is…
There is compelling evidence that at least some clusters of galaxies are powerful sources of non-thermal radiation. In all cases where this radiation has been detected, a general trend is that high energy densities of cosmic rays and…
There has been extensive recent progress in X-ray observations of clusters of galaxies with the analysis of the entire ASCA database and recent new results from Beppo-SAX, Chandra, and XMM-Newton. The temperature profiles of most clusters…
Long arcs in clusters of galaxies, produced by gravitational lensing, can be used to estimate the mass interior to the arcs and therefore, constrain the cluster mass distribution. The radial density distribution of the intracluster gas…
Clusters of galaxies are self-gravitating systems of mass ~10^14-10^15 Msun. They consist of dark matter (~80 %), hot diffuse intracluster plasma (< 20 %) and a small fraction of stars, dust, and cold gas, mostly locked in galaxies. In most…
We review recent progress in the description of the formation and evolution of galaxy clusters in a cosmological context by using numerical simulations. We focus our presentation on the comparison between simulated and observed X-ray…
Most of the baryons in the present-day universe are thought to reside in intergalactic space at temperatures of 10^5-10^7 K. X-ray emission from these baryons contributes a modest (~10%) fraction of the ~ 1 keV background whose prominence…
The study of galaxy cluster outskirts has emerged as one of the new frontiers in extragalactic astrophysics and cosmology with the advent of new observations in X-ray and microwave. However, the thermodynamic properties and chemical…
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…
The determination of galaxy cluster mass is of great importance since it is directly linked to the well- known problem of dark matter in the Universe and to the cluster baryon content. X-ray observations from satellites have enabled a…
Until recently, only about 10% of the total intracluster gas volume had been studied with high accuracy, leaving a vast region essentially unexplored. This is now changing and a wide area of hot gas physics and chemistry awaits discovery in…
Studies of the diffuse X-ray emitting gas in galaxy clusters have provided powerful constraints on cosmological parameters and insights into plasma astrophysics. However, measurements of the faint cluster outskirts have become possible only…
Clusters of galaxies as the largest clearly defined objects in our Universe are ideal laboratories to study the distribution of the most abundant chemical elements heavier than hydrogen and helium and the history of their production. The…
Clusters of galaxies at high redshift (z>1) are vitally important to understand the evolution of the large scale structure of the Universe, the processes shaping galaxy populations and the cycle of the cosmic baryons, and to constrain…
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.…
In the local universe, a large fraction of the baryon content is believed to exist as diffuse gas in filaments. While this gas is directly observable in X-ray emission around clusters of galaxies, it is primarily studied through its UV…
The existence of cosmic rays and weak magnetic fields in the intracluster volume has been well proven by deep radio observations of galaxy clusters. However a detailed physical characterization of the non-thermal component of large…
Some clusters of galaxies have been identified as powerful sources of non-thermal radiation, from the radio to X-ray wavelengths. The classical models proposed for the explanation of this radiation usually require large energy densities in…