Related papers: "Observing" Unrelaxed Clusters in Dark Matter Simu…
We report on the results from an ongoing program aimed at testing Newton's law of gravity in the low acceleration regime using globular clusters. It is shown that all clusters studied so far do behave like galaxies, that is, their velocity…
Increasing evidences provided primarily by the cluster lensing and numerical simulations of cluster formation indicate that galaxy clusters may contain compact cores that are substantially smaller than the cores revealed by the X-ray…
The distribution of offsets between the brightest cluster galaxies of galaxy clusters and the centroid of their dark matter distributions is a promising probe of the underlying dark matter physics. In particular, since this distribution is…
We study the effects of peculiar velocities on statistical measures of galaxy clustering. These effects occur when distances to the galaxies are estimated from their redshifts. It is assumed that the clustering pattern results from the…
Using numerical simulations of cluster formation in the standard CDM model (SCDM) and in a low-density, flat CDM model with a cosmological constant (LCDM), we investigate the gravitational lensing explanation for the reported associations…
We report on work done by the Virgo consortium, an international collaboration set up in order to study the formation and evolution of Large Scale Structure using N-body simulations on the latest generation of parallel supercomputers. We…
In hierarchical clustering, galaxy clusters accrete mass through the aggregation of smaller systems. Thus, the velocity field of the infall regions of clusters contains significant random motion superimposed on radial infall. Because the…
Clusters of galaxies are the largest gravitationally bound systems and therefore provide an important way of studying the formation and evolution of the large scale structure of the Universe. Cluster evolution can be inferred from…
We present a new method for measuring the projected mass distributions of galaxy clusters. The gravitational amplification is measured by comparing the joint distribution in redshift and magnitude of galaxies behind the cluster with that of…
We present the first study of evolution of galaxy groups in the Illustris simulation. We focus on dynamically relaxed and unrelaxed galaxy groups representing dynamically evolved and evolving galaxy systems, respectively. The evolutionary…
We present a comprehensive space-based study of ten X-ray luminous galaxy clusters (L_X>=8e44erg/s[0.1-2.4keV]) at z=0.2. Hubble Space Telescope observations reveal numerous gravitationally-lensed arcs for which we present four new…
We use the MACSIS hydrodynamical simulations to estimate the extent of gas clumping in the intracluster medium of massive galaxy clusters and how it affects the hydrostatic mass bias. By comparing the clumping to the azimuthal scatter in…
1) Background: the budget of non-thermal energy in galaxy clusters is not well constrained, owing to the observational and theoretical difficulties in studying these diluted plasmas on large scales. 2) Method: we use recent cosmological…
We investigate how the dynamical state of galaxy clusters influences their galaxy populations and mass distributions. Using photometrically selected clusters from the DESI Legacy Imaging Survey cross-matched with the UNIONS galaxy shear…
In spite of the promise of new techniques for constraining the mass distribution in galaxy clusters, much remains to be learned from galaxy orbital velocities. This article reviews the theory of potential estimation in hot dynamical systems…
We present the analysis of a local (z = 0.04 - 0.2) sample of 31 galaxy clusters with the aim of measuring the density of the X-ray emitting gas in cluster outskirts. We compare our results with numerical simulations to set constraints on…
Although numerous studies of individual galaxy clusters have demonstrated the presence of significant substructure, previous studies of the distribution of masses of galaxy clusters determined from optical observations have failed to…
The velocity distribution of spheres rolling on a slightly tilted rectangular two dimensional surface is obtained by high speed imaging. The particles are excited by periodic forcing of one of the side walls. Our data suggests that strongly…
We analyze the internal velocity dispersions of a sample of 172 nearby galaxy clusters (z < 0.15), each of which has at least 30 available galaxy redshifts, and spans a large richness range. Cluster membership selection is based on…
Merging of galaxy clusters are some of the most energetic events in the Universe, and they provide a unique environment to study galaxy evolution. We use a sample of 84 merging and relaxed SPT galaxy clusters candidates, observed with the…