相关论文: Scaling relations for dark matter core density and…

Galaxy clusters' structure, dominated by dark matter, is traced by member galaxies in the optical and hot intra-cluster medium (ICM) in X-rays. We compare the radial distribution of these components and determine the mass-to-light ratio vs.…

We perform a series of high-resolution N-body simulations designed to examine the density profiles of dark matter halos. From 12 simulated halos ranging the mass of $2\times10^{12}\sim 5\times10^{14} h^{-1}{\rm M_\odot}$ (represented by…

The cusped NFW universal density profile suggested by typical CDM models has been challenged in recent years by the discoveries of the soft cores for a broad range of masses from dwarf galaxies to clusters of galaxies. It is thus desirable…

We present the first results of a serendipitous search for clusters of galaxies in deep ROSAT-PSPC pointed observations at high galactic latitude. The survey is being carried out using a Wavelet based Detection Algorithm which is not biased…

The influence of cool galaxy cluster cores on the X-ray luminosity--gravitational mass relation is studied with Chandra observations of 64 clusters in the HIFLUGCS sample. As preliminary results we find (i) a significant offset of cool core…

We investigate the form and evolution of the X-ray luminosity-temperature (LT) relation of a sample of 114 galaxy clusters observed with Chandra at 0.1<z<1.3. The clusters were divided into subsamples based on their X-ray morphology or…

I re-examine mass estimates of the Coma cluster from pre-ASCA X-ray spectral observations. A large range of model dark matter distributions are examined, under the assumptions of hydrostatic equilibrium and spherical symmetry, to determine…

We analyze strongly lensed images in 8 galaxy clusters to measure their dark matter density profiles in the radial region between 10 kpc and 150 kpc, and use this to constrain the self-interaction cross section of dark matter (DM)…

We investigate galaxy clustering and galaxy-mass correlations in the LCDM cosmological model using a large volume SPH simulation. For the most part, the predicted biases between galaxies and dark matter lead to good agreement with current…

We present the integrated mass profiles for a sample of ten nearby (z<=0.15), relaxed galaxy clusters, covering a temperature range of [2-9]keV, observed with XMM-Newton. The mass profiles were derived from the observed gas density and…

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…

Imaging data from the Sloan Digital Sky Survey is used to measure the empirical size-richness relation for a large sample of galaxy clusters. Using population subtraction methods, we determine the radius at which the cluster galaxy number…

We present a comprehensive mass reconstruction of the rich galaxy cluster Cl 0024+17 at z~0.4 from ACS data, unifying both strong- and weak-lensing constraints. The weak-lensing signal from a dense distribution of background galaxies (~120…

We use a sample of 115 galaxy clusters at 0.1<z<1.3 observed with Chandra ACIS-I to investigate the relation between luminosity and Yx (the product of gas mass and temperature). The scatter in the relation is dominated by cluster cores, and…

We study the effects of mass and force resolution on the density profiles of galaxy-size Cold Dark Matter (CDM) halos in a flat, low-density cosmological model with vacuum energy. We show thatalthough increasing the mass and force…

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…

To investigate the relationships between dynamical status and other important characteristics of galaxy clusters, we conducted a study of X-ray cluster morphology using a sample of 101 clusters at redshift z=0.05-1 taken from the Chandra…

We investigate the levels of small scale structure in surface brightness images of the core of the X-ray bright cool-core galaxy cluster AWM 7. After subtraction of a model of the smooth cluster emission, we find a number of approximately…

Mass models of 15 nearby dwarf and spiral galaxies are presented. The galaxies are selected to be homogeneous in terms of the method used to determine their distances, the sampling of their rotation curves (RCs) and the mass-to-light ratio…

The total mass of clusters of galaxies is a key parameter to study massive halos. It relates to numerous gravitational and baryonic processes at play in the framework of large scale structure formation, thus rendering its determination…