相关论文: The Physics of Cluster Mergers

Recent observations reveal detailed structures of mergers in galaxy clusters. Moving cold fronts could be identified as remnants of subclusters. They are believed to mark the late stage of a merging process. Dynamics, geometry and extension…

(Abridged) We present a parameter study of offset mergers between clusters of galaxies. Using the Eulerian hydrodynamics/N-body code COSMOS, we simulate mergers between nonisothermal, hydrostatic clusters with a steep central dark matter…

Clusters of galaxies can be seen as giant astrophysical laboratories enclosing matter in a large enough volume, so that the matter composition can be taken as representing the composition of our Universe. X-ray observations allow a very…

The gravitational clustering hierarchy and dissipative gas processes are both involved in the formation of bulges. Here we present a simple empirical model in which bulge material is assembled via gravitational accretion of the visible…

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…

Relevant studies of the non-thermal components of the intracluster medium are performed at radio wavelengths. A number of clusters, indeed, exhibits cluster-wide diffuse radio emission, which is indication of the existence of large scale…

In the hierarchical structure formation model, clusters of galaxies form through a sequence of mergers and continuous mass accretion, which generate significant random gas motions especially in their outskirts where material is actively…

This review focuses on how galaxies and their globular cluster systems form. I first discuss the now fairly convincing evidence that some globular clusters form in galaxy starbursts/mergers. One way these observations are valuable is they…

The abundance and internal characteristics of rich clusters of galaxies can provide useful constraints on models of large--scale structure formation. This article will review some recent three dimensional, multi--fluid simulations of…

We have performed N-body simulations of poor clusters with enough particles to resolve the individual galaxies. The main cases of initial conditions are: (i) 50 equal mass galaxies; (ii) 60 galaxies with masses drawn from a Schechter…

The formation process, properties, and spatial distribution of galaxy groups and clusters are closely related to the background cosmological model. We use numerical simulations of variants of the CDM model with different cosmological…

Galaxy clusters grow by merging with other clusters, giving rise to Mpc-wide shock waves that travel at 1000-2500 km/s through the intra-cluster medium. To study the effects of merger shocks on the properties of cluster galaxies, we present…

Using a hydrodynamics plus N-body simulation of galaxy cluster formation within a large volume and mock Chandra X-ray observations, we study the form and evolution of the intrinsic scatter about the best-fit X-ray temperature-mass relation…

Massive stars blow powerful winds and eventually explode as supernovae. By doing so, they inject energy and momentum in the circumstellar medium, which is pushed away from the star and piles up to form a dense and expanding shell of gas.…

The hot X-ray emitting plasma in galaxy clusters is predicted to have turbulent motions which can contribute around ten percent of the cluster's central energy density. We report deep Chandra X-ray Observatory observations of the Coma…

We report evidence for enhanced quenching in low-redshift galaxy clusters hosting radio relics. This effect is strongest for low-mass galaxies and is consistent with a rapid quenching of star formation. These results imply that merger…

With ENZO simulations run on the J\"ulich supercomputers, we have investigated the evolution of magnetic fields in the largest cosmic structures (namely galaxy clusters and filaments connecting them) with unprecedented dynamical range.…

Galaxies in clusters are more likely to be of early type and to have lower star formation rates than galaxies in the field. Recent observations and simulations suggest that cluster galaxies may be `pre-processed' by group or filament…

We study the shape and evolution of the star formation main sequence in three independently developed semi-analytic models of galaxy formation. We focus, in particular, on the characterization of the model galaxies that are significantly…

We apply the idea that dense stellar systems in the central region of galaxies are formed via globular cluster mergers to the formation of the nuclear star cluster of the Milky Way, where a massive black hole is present. Our high precision…