相关论文: Using supercluster geometry as a cosmological prob…

Modern redshift surveys such as the 2 degree field Galaxy Redshift Survey (2dFGRS) and the Sloan Digital Sky Survey (SDSS) reveal the fully 3 dimensional distribution of a million or so galaxies over a large cosmological volume. Visually…

While clusters of galaxies are considered one of the most important cosmological probes, the standard spherical modelling of the dark matter and the intracluster medium is only a rough approximation. Indeed, it is well established both…

In this paper we summarize the main properties of the ENACS (the ESO Nearby Abell Cluster Survey), which was one of the ESO Keyprogrammes carried out in the first half of the 1990's, and we discuss some recent work on the properties of the…

We present a morphological study of galaxies in the A901/902 supercluster from the COMBO-17 survey. A total of 570 galaxies with photometric redshifts in the range 0.155 < z_phot < 0.185 are visually classified by three independent…

We study the dipole for a redshift sample of Abell/ACO clusters. To elucidate the constraints it places on dark matter models, we use numerical simulations based on the Zel'dovich approximation. We run 20 realizations of each of six…

We report the discovery of two highly extended filaments and one extremely high density knot within the region of Aquarius. The supercluster candidates were chosen via percolation analysis of the Abell and ACO catalogs and include only the…

Luminous stars in background galaxies straddling the lensing caustic of a foreground galaxy cluster can be individually detected due to extreme magnification factors of $\sim 10^2$--$10^3$, as recently observed in deep HST images. We…

We have performed an isophotal analysis of galaxies in the distant (z=0.4) cluster Cl0939+4713 (Abell 851), using post-refurbished Hubble Space Telescope images. Morphological type estimates for the galaxies are given. A rigorous comparison…

We study the distribution of X-ray selected clusters of galaxies with respect to superclusters determined by Abell clusters of galaxies and show that the distribution of X-ray clusters follows the supercluster-void network determined by…

The interstellar medium has a highly filamentary and hierarchical structure, which may play a significant role in star formation. A systematical study on the large-scale filaments towards their physical parameters, distribution, structures…

From ROSAT data, the bright X-ray cluster Abell 85 was found to show a roughly symmetrical shape, on to which are superimposed several features, among which: (1) a blob or group of galaxies falling on to the main cluster, with the gas in…

Filaments of the cosmic web have long been associated with the threadlike structures seen in galaxy redshift surveys. However, despite their baryon content being dominated by hot gas, these filaments have been an elusive target for X-ray…

The distribution of Abell clusters of galaxies is analysed to study the regularity of the supercluster-void network. A new geometric method sensitive to the regularity of the location of clusters is applied. We find that the…

Using the APM cluster data we investigate whether the dynamical status of clusters is related to the large-scale structure of the Universe. We find that cluster substructure is strongly correlated with the tendency of clusters to be aligned…

The morphology of galaxy clusters is quantified using Minkowski functionals, especially the vector-valued ones, which contain directional information and are related to curvature centroids. The asymmetry of clusters and the amount of their…

We combine multi-object spectroscopy from the 2dF and EFOSC2 spectrographs with optical imaging of the inner 30'x30' of A2384 taken with the ESO Wide Field Imager. We carry out a kinematical analysis using the EMMIX algorithm and biweight…

Observations reveal that on large scales the universe is spanned by a percolating network of superclusters interspersed with large and almost empty regions -- voids. This thesis reports the construction of a sophisticated computational…

Stars form in dense, dusty structures, which are embedded in larger clumps of molecular clouds often showing a clear filamentary structure on large scales (> 1pc). One of the best-studied regions in the Hi-GAL survey can be observed toward…

We use ensembles of high-resolution CDM simulations to investigate the shape and amplitude of the two point correlation function of rich clusters. The standard scale-invariant CDM model with $\Omega=1$ provides a poor description of the…

We present a detailed study of the morphological features of 22 rich galaxy clusters. Our sample is constructed from a cross-correlation of optical (Abell+APM) data with X-ray (0.1 - 2.4) keV ROSAT pointed observations. We systematically…