相关论文: The Empirical X-Ray Luminosity - Gravitational Mas…
It is shown that galaxy cluster surveys selecting clusters by their X-ray luminosity effectively select by cluster mass. It is shown that a selection based solely on Abell galaxy richness is less efficient in terms of mass. Furthermore the…
Using the brightest clusters in the ROSAT All-Sky Survey we compiled an X-ray flux-limited sample of galaxy clusters. The clusters have been reanalysed using ROSAT PSPC pointed observations if possible. The gravitational mass has been…
We present the first measurement of the mass function of galaxy clusters based directly on cluster masses derived from observations of weak gravitational lensing. To investigate the degree of sample incompleteness resulting from the X-ray…
We present a statistical comparison of three different estimates of cluster mass, namely, the dynamical masses obtained from the velocity dispersion of optical galaxies, the X-ray masses measured from the temperature of X-ray emitting gas…
One hundred and six galaxy clusters have been studied in detail using X-ray data and important global physical properties have been determined. Correlations between these properties are studied with respect to the description of clusters as…
The original abstract significantly exceeds the space available here, so here's a brief summary. The abstract is similar to the abstract of astro-ph/0111285 (ApJ, 567, 716) which describes the X-ray galaxy cluster sample HIFLUGCS, the X-ray…
A new X-ray selected and X-ray flux-limited galaxy cluster sample is presented. Based on the ROSAT All-Sky Survey the 63 brightest clusters with galactic latitude |bII| >= 20 deg and flux fx(0.1-2.4 keV) >= 2 * 10^{-11} ergs/s/cm^2 have…
Gravitational lensing by clusters of galaxies has been detected on scales ranging from $\sim10^{-1}$ Mpc to $\sim10$ Mpc, namely, arcs/arclets, weak lensing and quasar-cluster associations. This allows us to derive an overall radius matter…
The review summarizes present and future applications of galaxy clusters to cosmology with emphasis on nearby X-ray clusters. The discussion includes the density of dark matter, the normalization of the matter power spectrum, neutrino…
Formation of dark matter halos is sensitive to the expansion rate of the Universe and to the growth of structures under gravitational collapse. Virialization of halos heats the gaseous intra-cluster medium to high temperatures, leading to…
We review the methods adopted to reconstruct the mass profiles in X-ray luminous galaxy clusters. We discuss the limitations and the biases affecting these measurements and how these mass profiles can be used as cosmological proxies.
We investigated the optical properties of 7 clusters of galaxies observed in three colors over the range of absolute magnitudes -24 < M < -12. Our aim is to estimate the Luminosity Function and the total cluster luminosity of our sample in…
Despite consistent progress in numerical simulations, the observable properties of galaxy clusters are difficult to predict ab initio. It is therefore important to compare both theoretical and observational results to a direct measure of…
The determination of galaxy cluster mass is of great importance since it is directly linked to the well- known problem of dark matter in the Universe and to the cluster baryon content. X-ray observations from satellites have enabled a…
The mass derived from gravitational lensing reflects the total mass contained in the lensing system, independent of the specific matter contents and states. A comparison of the dynamical masses from hydrostatic equilibrium with the…
[Abridged] In the past 15 years, the concentration-mass relation has been investigated diffusely in theoretical studies. On the other hand, only recently has this relation been derived from X-ray observations. When that happened, the…
We consider the possibility that masses and gravitational potentials of galaxy cluster, estimated at X-ray wavelengths, could be explained without assuming huge amounts of dark matter, but in the context of $f(R)$-gravity. Specifically, we…
The mass function of galaxies and clusters of galaxies can be derived observationally based on different types of observations. In this study we test if these observations can be combined to a consistent picture which is also in accord with…
Clusters of galaxies are used in a variety of ways to do cosmology. Some of them are presented here. Their X-ray emitting gas allows us to determine the baryon fraction, dark matter distribution and the matter density $\Omega_{m}$ of the…
Whether the X-ray luminosities of clusters of galaxies evolve has been a contentious issue for over ten years. However, the data available to address this issue have improved dramatically as cluster surveys from the ROSAT archive near…