Related papers: Studying galaxy cluster morphological metrics with…
We stacked the X-ray data from the ROSAT All Sky Survey for over 4,000 clusters selected from the 2MASS catalog and divided into five richness classes. We detected excess X-ray emission over background at the center of the stacked images in…
(Abridged) We present a morphological analysis of 17 X-ray selected clusters at z~0.25, imaged uniformly with HST WFPC2. Eight of these clusters have low X-ray luminosities (<10^{44} erg/s), while the remaining nine clusters have…
We present a detailed study of relaxed and unrelaxed galaxy clusters in a large dark-matter only simulation. Recent work has demonstrated clear differences between the galaxy populations in clusters which have Gaussian velocity…
The upcoming XMM Large Scale Structure Survey (XMM-LSS) will ultimately provide a unique mapping of the distribution of X-ray sources in a contiguous 64 sq. deg. region. In particular, it will provide the 3-dimensional location of about 900…
We present a very large high-resolution cosmological N-body simulation, the Millennium-XXL or MXXL, which uses 303 billion particles to represent the formation of dark matter structures throughout a 4.1Gpc box in a LambdaCDM cosmology. We…
Despite compelling theoretical arguments, the use of clusters as cosmological probes is, in practice, frequently questioned because of the many uncertainties impinging on cluster mass estimates. Our aim is to develop a fully self-consistent…
Galaxy clusters have their unique advantages for cosmology. Here we collect a new sample of 10 lensing galaxy clusters with X-ray observations to constrain cosmological parameters.The redshifts of lensing clusters lie between 0.1 and 0.6,…
The largest uncertainty for cosmological studies using clusters of galaxies is introduced by our limited knowledge of the statistics of galaxy cluster structure, and of the scaling relations between observables and cluster mass. A large…
Large area surveys have detected significant samples of galaxy clusters that can be used to constrain cosmological parameters, provided that the masses of the clusters are measured robustly. To improve the calibration of cluster masses…
Dynamical state of galaxy clusters is closely related to their observational properties in X-ray, optical and radio wavelengths. We develop a method to diagnose the substructure and dynamical state of galaxy clusters by using photometric…
Numerous metrics exist to quantify the dynamical state of galaxy clusters, both observationally and within simulations. Many of these correlate strongly with one another, but it is not clear whether all of these measures probe the same…
We have studied morphological evolution in clusters simulated in the adiabatic limit and with radiative cooling. Cluster morphology in the redshift range, $0 < z < 0.5$, is quantified by multiplicity and ellipticity. In terms of…
We investigate how observations of strong lensing can be used to infer cosmological parameters, in particular the equation of state of dark energy. We focus on the growth of the critical lines of lensing clusters with the source redshift as…
We study a sample of 207 nearby galaxy groups and clusters observed with XMM-Newton. Key aspects of this sample include the large size, the high data quality, and the large diversity of cluster dynamical states. We determine the overall…
We explore the morphological and dynamical evolution of galaxy clusters in simulations using scalar and vector-valued Minkowski valuations and the concept of fundamental plane relations. In this context, three questions are of fundamental…
Galaxy clusters provide a unique environment to study galaxy evolution. The role of cluster dynamical states in shaping the physical and morphological properties of member galaxies remains an open question. We aim to assess the impact of…
We consider a sample of 51 distant galaxy clusters at 0.15<z<0.9 (<z> about 0.3), each cluster having at least 10 galaxies with available redshift in the literature. We select member galaxies, analyze the velocity dispersion profiles, and…
According to the cosmological principle, galaxy cluster sizes and cluster densities, when averaged over sufficiently large volumes of space, are expected to be constant everywhere, except for a slow variation with look-back time (redshift).…
We analyse the correlation function of mock galaxy clusters in redshift space. We constructed several mock catalogues designed to mimic the selection biases inherent in a variety of observational surveys. We explore different effects that…
Results of a systematic study of substructure in X-ray surface brightness distributions of a combined sample of 470 REFLEX+BCS clusters of galaxies are presented. The fully automized morphology analysis is based on data of the 3rd…