Related papers: A 140 Mpc Oscillation of the Abell Cluster Correla…
Using a new spectroscopic sample and methods accounting for spectroscopic sampling fractions that vary in magnitude and surface brightness, we present R-band galaxy luminosity functions (GLFs) for six nearby galaxy clusters with redshifts…
In a recent publication, the flexion aperture mass statistic was found to provide a robust and effective method by which substructure in galaxy clusters might be mapped. Moreover, we suggested that the masses and mass profile of structures…
We report on the results from two independent but complementary statistical analyses of the WMAP first-year data, based on the power spectrum and N-point correlation functions. We focus on large and intermediate scales (larger than about 3…
One possible way to investigate the nature of the primordial power spectrum fluctuations is by investigating the statistical properties of the local maximum in the density fluctuation fields. In this work we present a study of the mean…
The position angles of a large number of Abell and Shectman clusters (in total 637 clusters), identified in the Lick map as surface density enhancements, are estimated. Using published redshifts for 277 of these I have detected strong…
We present results from a pilot study of a new wide-field, multicolour (BVR) CCD imaging project, designed to examine galaxy evolution along large scale filaments that connect clusters of galaxies at intermediate redshifts (0.08 < z <…
We have observed 433 z<=0.08 brightest cluster galaxies (BCGs) in a full-sky survey of Abell clusters. The BCG Hubble diagram is consistent to within 2% of a Omega_m=0.3, Lambda=0.7 Hubble relation. The L_m-alpha relation for BCGs, which…
Deep imaging data from the Keck II telescope are employed to study the globular cluster (GC) populations in the cores of six rich Abell clusters. The sample includes A754, A1644, A2124, A2147, A2151, and A2152, and spans the redshift range…
We compute the angular two-point correlation functions of the gamma-ray bursts at cosmological distances. Since the gamma-ray burst emission mechanism is not yet established, we simply assume that the gamma-ray burst sources are associated…
The angular two-point correlation function is calculated for the first 300 square degrees of the FIRST radio survey. Results for various subsamples are also obtained. Double-lobed sources are shown to have a higher clustering amplitude than…
High-cadence optical observations of an H-alpha blue-wing bright point near solar AR NOAA 10794 are presented. The data were obtained with the Dunn Solar Telescope at the National Solar Observatory/Sacramento Peak using a newly developed…
We show that the spatial correlation function of a flux-limited sample of X-ray selected clusters of galaxies will exhibit a correlation scale that is smaller than the correlation scale of a volume-limited, richness-limited sample of…
We present the Planck likelihood, a complete statistical description of the two-point correlation function of the CMB temperature fluctuations. We use this likelihood to derive the Planck CMB power spectrum over three decades in l, covering…
We study the possible rotation of cluster galaxies, developing, testing and applying a novel algorithm which identifies rotation, if such does exist, as well as its rotational centre, its axis orientation, rotational velocity amplitude and,…
We present quantitative investigations of the weak lensing effect on the two-point correlation functions of local maxima (hotspots), $\xipk(\theta)$, in the cosmic microwave background (CMB) maps. The lensing effect depends on the projected…
One of the main problems of observational cosmology is to determine the range in which a reliable measurement of galaxy correlations is possible. This corresponds to determine the shape of the correlation function, its possible evolution…
We report numerical simulations of two-dimensional $q$-state Potts models with emphasis on a new quantity for the computation of spatial correlation lengths. This quantity is the cluster-diameter distribution function $G_{diam}(x)$, which…
We measure the large-scale intrinsic alignments of galaxy clusters in the Sloan Digital Sky Survey (SDSS) using subsets of two cluster catalogues: 6625 clusters with 0.1<z<0.3 from the maxBCG cluster catalogue (Koester et al. 2007, 7500 sq.…
We present two new catalogues of superclusters of galaxies out to a redshit of z = 0.15, based on the Abell/ACO cluster redshift compilation maintained by one of us (HA). The first of these catalogues, the all-sky Main SuperCluster…
Using a combination of near-infrared and optical photometry, along with multi-object spectroscopy, we have confirmed the existence of a high-redshift cluster of galxies at z = 0.96. The cluster was found using a wide-angle tailed radio…