相关论文: Measuring the 3D shape of X-ray clusters
We use the RASS-SDSS galaxy cluster sample to compare the quality of optical and X-ray luminosities as predictors of other cluster properties such as their masses, temperatures, and velocity dispersions. We use the SDSS spectroscopic data…
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 constrain gas inflow speeds in star-forming galaxies with color gradients consistent with inside-out disk growth. Our method combines new measurements of disk orientation with previously described circumgalactic absorption in background…
This is the third of a series of papers in which we derive simultaneous constraints on cosmological parameters and X-ray scaling relations using observations of the growth of massive, X-ray flux-selected galaxy clusters. Our data set…
We use the Fifth Data Release of the Sloan Digital Sky Survey to study X-ray-selected galaxy groups and compare their properties to clusters. We search for infall patterns around the groups and use these to measure group mass profiles to…
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…
Observations of the evolution of the galaxy cluster X-ray luminosity function suggest that the entropy of the intra-cluster medium plays a significant role in determining the development of cluster X-ray properties. I present a theoretical…
The GEMS project involves a multi-wavelength study of a sample of 60 galaxy groups. Substantial ROSAT PSPC observations are used to characterise the state of the intergalactic medium in each. We present the results of a uniform analysis of…
The principles of measuring the shapes of galaxies by a model-fitting approach are discussed in the context of shape-measurement for surveys of weak gravitational lensing. It is argued that such an approach should be optimal, allowing…
During cluster mergers, the intracluster gas and member galaxies undergo dynamic evolution, but at different timescales and reach different states. We collect 24 galaxy clusters in quasi-equilibrium state as indicated by the X-ray image,…
We compare the empirical relationships between the mass of a galaxy's globular system M_GCS, the gas mass in the hot X-ray atmosphere M_X within a fiducial radius of 5 r_e, the total gravitational mass M_grav within 5 r_e, and lastly the…
While the use of galaxy clusters as {\it tools} to probe cosmology is established, their conventional description still relies on the spherical and/or isothermal models that were proposed more than 20 years ago. We present, instead, a…
We propose a method to map the temperature distribution of the hot gas in galaxy clusters that uses resolved images of the thermal Sunyaev-Zel'dovich (tSZ) effect in combination with X-ray data. Application to images from the New IRAM KIDs…
Clusters of galaxies contain a hot gas, which emits in X-rays. X-ray telescopes such as XMM-Newton allow to study this plasma to obtain information on physical quantities of these objects. We present here some results on the total mass…
A new method for a simultaneous search for clusters of galaxies in X-ray photon maps and optical galaxy maps is described. The merging of X-ray and optical data improves the source identification so that a large amount of telescope time for…
Temperature of the hot gas in galaxy clusters is known to be a reliable proxy for their total gravitating mass, allowing one to use spectroscopic X-ray observations for halo mass function measurements. Data of shallow wide area surveys,…
Numerical hydro-N-body simulations are very important tools for making theoretical predictions for the formation of galaxy clusters. They show that the atmospheres of clusters of galaxies have quite complex angular and thermal structures.…
The structural parameters of a magnitude-limited sample of 148 unbarred S0-Sb galaxies were derived using the GASP2D algorithm and then analyzed to derive the intrinsic shape of their bulges. We developed a new method to derive the…
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…
The X-ray emission from a simulated massive stellar cluster is investigated. The emission is calculated from a 3D hydrodynamical model which incorporates the mechanical feedback from the stellar winds of 3 O-stars embedded in a giant…