相关论文: Scanning the Universe for Large-Scale Structures u…
I review recent progress in the study of the large-scale structure of the Universe through the distribution of clusters of galaxies, concentrating on new results using X-ray selected samples. After discussing the importance of understanding…
High-redshift clusters of galaxies are amongst the largest cosmic structures. Their properties and evolution are key ingredients to our understanding of cosmology: to study the growth of structure from the inhomogeneities of the cosmic…
The properties of globular cluster systems (GCSs) in the core of the nearby galaxy clusters Fornax and Hydra I are presented. In the Fornax cluster we have gathered the largest radial velocity sample of a GCS system so far, which enables us…
In recent years, the outskirts of galaxy clusters have emerged as one of the new frontiers and unique laboratories for studying the growth of large scale structure in the universe. Modern cosmological hydrodynamical simulations make firm…
We present a photometric investigation of the globular cluster population of NGC 1399, the central galaxy in the Fornax cluster, in Washington C and Kron R filters within a field of 36'x36'. This is the largest area around this galaxy ever…
The fractal dimension of large-scale galaxy clustering has been demonstrated to be roughly $D_F \sim 2$ from a wide range of redshift surveys. If correct, this statistic is of interest for two main reasons: fractal scaling is an implicit…
The large supercluster structures obvious in recent galaxy redshift surveys are quantified using an one-dimensional cluster analysis (core sampling) and a three-dimensional cluster analysis based on the minimal spanning tree. The comparison…
The distribution of galaxies up to a distance of 200 Mpc (650 million light-years) is flat and shows a structure like a shell roughly centered on the Local Supercluster (Virgo cluster). This result clearly confirms the existence of the…
We present a comprehensive high spatial-resolution imaging study of globular clusters (GCs) in NGC1399, the central giant elliptical cD galaxy in the Fornax galaxy cluster, conducted with HST/ACS. Using a novel technique to construct…
Gamma-ray bursts (GRBs) are detectable out to very large distances and as such are potentially powerful cosmological probes. Historically, the angular distribution of GRBs provided important information about their origin and physical…
The 26 long-duration gamma-ray bursts (GRBs) with known redshifts form a distinct cosmological set, selected differently than other cosmological probes such as quasars and galaxies. Since the progenitors are now believed to be connected…
With the advent of galaxy surveys which provide large samples of galaxies or galaxy clusters over a volume comparable to the horizon size (SDSS-III, HETDEX, Euclid, JDEM, LSST, Pan-STARRS, CIP etc.) or mass-selected large cluster samples…
Recent work on globular cluster systems in dwarf galaxies outside the Local Group is reviewed. Recent large imaging surveys with the Hubble Space Telescope and follow-up spectroscopy with 8-m class telescopes now allow us to compare the…
Galaxy clusters are thought to grow hierarchically through the continuous merging and accretion of smaller structures across cosmic time. In the local Universe, these phenomena are still active in the outer regions of massive clusters…
A new semianalytical model that explains the formation and sizes of the 'great walls' - the largest structures observed in the universe is suggested. Although the basis of the model is the Zel'dovich approximation it has been used in a new…
Clusters of galaxies are one of the few prominent classes of objects predicted to emit gamma rays not yet detected by satellites like EGRET or ground-based Imaging Atmospheric Cherenkov Telescopes (IACTs). The detection of Very High Energy…
As the largest, clearly defined building blocks of our Universe, galaxy clusters are interesting astrophysical laboratories and important probes for cosmology. X-ray surveys for galaxy clusters provide one of the best ways to characterise…
Based on the most complete sample of Galactic open star clusters up to 1.8 kpc, we performed statistical analysis of the distribution of open cluster parameters in order to understand the Galactic structure. The geometrical characteristics…
The recent measurement of the gravitational redshifts of galaxies in galaxy clusters by Wojtak et al. has opened a new observational window on dark matter and modified gravity. By stacking clusters this determination effectively used the…
This paper presents the first results of an Halpha imaging survey of galaxies in the central regions of the A2151 cluster. A total of 50 sources were detected in Halpha. The morphologies of the 43 H$\alpha$ selected galaxies range from…