相关论文: Arc Statistics in Clusters: Galaxy Contribution
It appears that the dynamical status of clusters and groups of galaxies is related to the large-scale structure of the Universe. A few interesting trends have been established: (1) The Cluster Substructure - Alignment Connection, by which…
We use numerical simulations of galaxy clusters in different cosmologies to study their ability to form large arcs. The cosmological models are: Standard CDM (SCDM; Omega_0=1, Omega_Lambda=0); tauCDM with reduced small-scale power…
Recent observations show a large concentration of galaxies at high redshift. At first sight strong clustering of galaxies at high redshifts seems to be in contradiction with the models of structure formation. In this paper we show that such…
We consider the effect of lensing magnification on high redshift sources in the case that magnification varies on the sky, as expected in wide fields of view or within observed galaxy clusters. We give expressions for number counts, flux…
Probabilistic cross-identification has been successfully applied to a number of problems in astronomy from matching simple point sources to associating stars with unknown proper motions and even radio observations with realistic morphology.…
Supernovae in distant galaxies that are gravitationally lensed by foreground galaxy clusters make excellent cosmological candles for measuring quantities like the density of the Universe in its various components and the Hubble constant.…
Clusters of galaxies are important laboratories for understanding both galaxy evolution and constraining cosmological quantities. Any analysis of clusters, however, is best done when one can reliably determine which galaxies are members of…
We present the results of a systematic search for gravitationally-lensed arcs in clusters of galaxies located in the Hubble Space Telescope Wide Field and Planetary Camera 2 data archive. By carefully examining the images of 128 clusters we…
The effect of stars on the lensing properties of the supermassive black hole in the Galactic Center is similar to the effect of planets on microlensing by a star. We show that the dense stellar cluster around SgrA* increases by factors of a…
Cluster strong lensing cosmography is a promising probe of the background geometry of the Universe and several studies have emerged, thanks to the increased quality of observations using space and ground-based telescopes. For the first…
The strong galaxy-galaxy lensing produces highly magnified and distorted images of background galaxies in the form of arcs and Einstein rings. Statistically, these effects are quantified, for example, in the number counts of highly luminous…
We present the first three galaxy clusters of a larger sample of the most X-ray luminous galaxy clusters selected from the ROSAT Bright Survey. This project, which is a systematic search for strong lensing, aims at arc statistics, mass…
Upcoming wide-area surveys in the submillimetre regime will allow the construction of complete galaxy cluster samples through their thermal Sunyaev-Zel'dovich effect. We propose an analytic method to predict the number of gravitationally…
Over the coming decade, the observational samples available for studies of cluster abundance evolution will increase from tens to hundreds, or possibly to thousands, of clusters. Here we assess the power of future surveys to determine…
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…
Magnification bias, an observational effect of gravitational lensing in the weak regime, allows testing the cosmological model through angular correlations of sources at different redshifts. This effect has been observed in various…
We examine whether a cosmologically significant distribution of dark galaxy group or cluster-sized objects can have an optical depth for multiple imaging of distant background sources which is comparable to that from known galaxies while at…
Recent observations, as well as theoretical studies, have suggested that stellar cluster formation may depend on local and global environmental properties. In particular, the fraction of stars that form within long-lived bound clusters…
We discuss the second order contributions to lensing statistics resulting from the clustering of background sources from which galaxy shape measurements are made in weak lensing experiments. In addition to a previously discussed…
The distribution of mass on galaxy cluster scales is an important test of structure formation scenarios, providing constraints on the nature of dark matter itself. Several techniques have been used to probe the mass distributions of…