Related papers: The Bullet Cluster is not a Cosmological Anomaly
Clusters of galaxies are studied from a theoretical point of view, comparing with observational results whenever possible. The problem is approached both analytically as well as by means of high-resoultion numerical simulations. The dark…
We present the results of a simple but robust morphological classification of a statis- tically complete sample of 108 of the most X-ray luminous clusters at 0.15 < z < 0.7 observed with Chandra. Our aims are to (a) identify the most…
The correlation function of galaxy clusters has often been used as a test of cosmological models. A number of assumptions are implicit in the comparison of theoretical expectations to data. Here we use an ensemble of ten large N-body…
The observational evidence for the acceleration of the universe demonstrates that canonical theories of gravitation and particle physics are incomplete, if not incorrect. A new generation of astronomical facilities will shortly be able to…
Combining XMM-Newton and Chandra data, we have performed a detailed study of Abell 3558. Our analysis shows that its dynamical history is more complicated than previously thought. We have found some traits typical of cool core clusters…
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…
If the accelerated expansion of the universe is due to a modification of general relativity at late times, it is likely that the growth of structure on large scales would also display deviations from the standard cosmology. We investigate…
We present DLSCL J0916.2+2951 (z=0.53), a newly discovered major cluster merger in which the collisional cluster gas has become dissociated from the collisionless galaxies and dark matter. We identified the cluster using optical and weak…
In galaxy cluster collisions, the gas can be separated from dark matter halos. Abell~56 displays signatures of a dissociative bullet-like merger with a possible high inclination angle between the plane of orbit and the sky. Our objective is…
We use the large catalogues of haloes available for the Millennium Simulation to test whether recently merged haloes exhibit stronger large-scale clustering than other haloes of the same mass. This effect could help to understand the very…
We have performed a series of N-body experiments on Connection Machine-5 in order to simulate the formation of galaxy clusters gravitationally dominated by a massive dark background. In accordance with previous authors we find an extremely…
We evolve for the first time in full general relativity a small, collisional N-body black hole cluster of arbitrary total mass M. The bound cluster is initially compact (radius R/M~10), stable, and consists of 25 equal-mass, nonspinning…
We present a detailed strong lensing, weak lensing and X-ray analysis of Abell 2744 (z = 0.308), one of the most actively merging galaxy clusters known. It appears to have unleashed `dark', `ghost', `bullet' and `stripped' substructures,…
We use numerical simulations of different dark energy cosmologies to investigate the concentration-mass (c-M) relation in galaxy clusters. In particular, we consider a reference Lambda cold dark matter (LambdaCDM) model, two models with…
We present an analysis of a highly asymmetric cluster merger from a Chandra observation of Abell 85. The merger shows significant disruption of the less massive subcluster from ram pressure effects. Nevertheless, a cold core, coincident…
The galaxy cluster 1E 0657-56 has a bullet-like subcluster that is moving away from the centre of the main cluster at high speed. Markevitch et al. (2004) recently estimated a relative velocity of V_bullet = 4500 +1100/-800 km/s, based on…
To investigate the dynamical properties of globular clusters, the surface brightness and kinematic data were collected and fitted to a family of lowered isothermal models called LIMEPY models. For 18 studied globular clusters, the amounts…
A clump moving through the intracluster medium of a galaxy cluster can drive a bow shock trailed by a bullet-like core. In some cases, such as in the prototypical Bullet cluster, X-rays show a gas bullet with a protruding head and…
Several simple mergers between model galaxy clusters containing a mixture of gas and dark matter are examined, testing the coupling of the gas to the underlying collisionless material. The gas is shocked, irreversibly dissipating the energy…
We show that, in flat $\Lambda$CDM, low-redshift structure probes -- cluster abundances, 3$\times$2-point analyses, and full-shape clustering -- are mutually consistent, jointly delivering precise constraints on $\sigma_8$ and $\Omega_{\rm…