相关论文: Concentrating the Dark Matter in Galaxy Clusters t…
We examine gravitational lensing constraints on the structure of galaxy clusters and compare them with the results of cosmological N-body simulations of cluster formation in cold dark matter (CDM) dominated universes. We find that cluster…
We use measurements of weak gravitational shear around a sample of massive galaxy clusters at z = 0.3 to constrain their average radial density profile. Our results are consistent with the density profiles of CDM halos in numerical…
We compile a sample of 38 galaxy clusters which have both X-ray and strong lensing observations, and study for each cluster the projected offset between the dominant component of baryonic matter center (measured by X-rays) and the…
We consider the infall of a massive clump into a dark-matter halo as a simple and extreme model for the effect of baryonic physics (neglected in gravity-only simulations of large-scale structure formation) on the dark-matter. We find that…
Locating the centers of dark matter halos is critical for understanding the mass profiles of halos as well as the formation and evolution of the massive galaxies that they host. The task is observationally challenging because we cannot…
The origin and formation of globular clusters has remained a mystery. We present a formation scenario for ancient globular cluster-like objects that form in ultra-high resolution simulations (smallest cell size $<0.1\,\mathrm{pc}$, mass…
Galaxy clusters form at the highest density nodes of the cosmic web. The clustering of massive halos is enhanced relative to the general mass distribution and matter beyond the virial region is strongly correlated to the halo mass (halo…
We investigated the evolution of clusters of galaxies using self-consistent $N$-body simulations in which each galaxy was modeled by many particles. We carried out simulations for about 20 cases using different initial conditions. In all…
We perform a general computational analysis of possible post-collision mass distributions in high-speed galaxy cluster collisions in the presence of weakly self-interacting dark matter. Using this analysis, we show that weakly…
We compare the central mass concentration of Cold Dark Matter halos found in cosmological N-body simulations with constraints derived from the Milky Way disk dynamics and from the Tully-Fisher relation. For currently favored values of the…
X-ray selected samples are known to miss galaxy clusters that are gas poor and have a low surface brightness. This is different for the optically selected samples such as the X-ray Unbiased Selected Sample (XUCS). We characterise the origin…
In collisions of galaxy clusters, the lack of displacement between dark matter and galaxies suggests that the dark matter scattering depth is small. This yields an upper limit on the dark matter cross section if the dark matter column…
We present X-ray and weak lensing observations of the merging cluster system 1E0657-556. Due to the recently collision of a merging subcluster with the main cluster, the X-ray plasma has been displaced from the cluster galaxies in both…
In recent years, the availability of large, complete cluster samples has enabled numerous cosmological parameter inference analyses using cluster number counts. These have provided constraints on the cosmic matter density $\Omega_m$ and the…
We examine the incidence of cold fronts in a large sample of galaxy clusters extracted from a (512h^-1 Mpc) hydrodynamic/N-body cosmological simulation with adiabatic gas physics computed with the Enzo adaptive mesh refinement code. This…
The existence of dark matter can be proved in an astrophysical context by the discovery of a system in which the observed baryons and the inferred dark matter are spatially segregated, such as the bullet cluster (1E0657-558). The full…
We study the total gravitating mass distribution in the central region of 23 clusters of galaxies with Chandra. Using a new deprojection technique, we measure the temperature and gas density in the very central region of the clusters as a…
The dynamical evolution of galaxies in clusters is modified if dark matter is self-interacting. Heat conduction from the hot cluster halo leads to evaporation of the relatively cooler galactic halos. The stellar distribution would…
The use of galaxy clusters as cosmological probes hinges on our ability to measure their masses accurately and with high precision. Hydrostatic mass is one of the most common methods for estimating the masses of individual galaxy clusters,…
We assess how much unused strong lensing information is available in the deep \emph{Hubble Space Telescope} imaging and VLT/MUSE spectroscopy of the \emph{Frontier Field} clusters. As a pilot study, we analyse galaxy cluster…