相关论文: The connection between X-ray Clusters and Star For…
While the concept of "clustering" primarily refers to galaxies, the fact is that galaxies can be neglected - at least in terms of mass - when considering the continuous competition between accretion and relaxation processes of dark matter…
The virialization shock around an X-ray cluster primarily heats the ions, since they carry most of the kinetic energy of the infalling gas. Subsequently, the ions share their thermal energy with the electrons through Coulomb collisions. We…
Clusters of galaxies are uniquely important cosmological probes of the evolution of the large scale structure, whose diagnostic power depends quite significantly on the ability to reliably determine their masses. Clusters are typically…
I review recent progress in the study of the large-scale structure of the Universe through the distribution of clusters of galaxies, concentrating on new results using X-ray selected samples. After discussing the importance of understanding…
Galaxy clusters form from the infall of dark and baryonic matter at the intersection of cosmic filaments. Most of the baryons are in the form of a hot, magnetized, intracluster plasma detected through its X-ray thermal bremsstrahlung…
New X-ray observations from the {\it Chandra} and XMM-{\it Newton} observatories have shown that cooling of the intracluster medium is occurring at rates that are now approaching the star formation rates measured in cD galaxies at the bases…
The radiative cooling time of the X-ray-emitting plasma near the center in many clusters of galaxies is shorter than the age of the cluster, but neither the expected large drop in central temperature --nor the expected mass flow towards the…
Gamma-ray astronomy will play a crucial role in the investigation of nonthermal processes in the large scale structure of the universe. Particularly, galaxy clusters (GC) observations at this photon energy will help us understand the origin…
X-ray observations of clusters at different redshifts are presented and compared. For the nearest cluster -- the Virgo cluster -- we show a comparison of the galaxy distribution and the distribution of the intra-cluster gas. Although the…
The properties of clusters of galaxies offer key insights into the assembly process of structure in the universe. Numerical simulations of cosmic structure formation in a hierarchical, dark matter dominated universe suggest that galaxy…
The state of the hot gas in clusters of galaxies is investigated with a set of model clusters, created by assuming a polytropic equation of state (Gamma=1.2) and hydrostatic equilibrium inside gravitational potential wells drawn from a dark…
The evolution of star clusters is determined by several internal and external processes. Here we focus on two dominant internal effects, namely energy exchange between stars through close encounters (two-body relaxation) and mass-loss of…
Cosmic rays produced in cluster accretion and merger shocks provide pressure to the intracluster medium (ICM) and affect the mass estimates of galaxy clusters. Although direct evidence for cosmic-ray ions in the ICM is still lacking, they…
I will briefly review various analytic approaches to understanding the contents and properties of the hot X-ray emitting gas contained in clusters and groups. Special emphases are given to the following three issues: (1)Reconstruction of…
The intensity of the soft X-Ray background is correlated with the distribution of galaxies. To demonstrate this, magnitude limited galaxy samples extracted from bright galaxy catalogues and the Lick counts are utilized. Significant…
We describe X-ray production in the atmospheres of hot, early-type stars in the framework of a ``stochastic shock model''. The extended envelope of a star is assumed to possess numerous X-ray emitting ``hot'' zones that are produced by…
Young stars form on a wide range of scales, producing aggregates and clusters with various degrees of gravitational self-binding. The loose aggregates have a hierarchical structure in both space and time that resembles interstellar…
We present a high-resolution set of adiabatic binary galaxy cluster merger simulations using FLASH. These are the highest-resolution simulations to date of such mergers using an AMR grid-based code with Eulerian hydrodynamics. In this first…
We consider the hypothesis that the formation of elliptical galaxies includes a phase in which star formation is mostly restricted to massive stars, with the bias towards high mass stars increasing with elliptical galaxy mass. The mass…
We review the possible roles of large scale shocks as particle accelerators in clusters of galaxies. Recent observational and theoretical work has suggested that high energy charged particles may constitute a substantial pressure component…