The supercluster-void network - II. An oscillating cluster correlation function (original) (raw)
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Astron J, 2002
We study the spatial distribution of Abell and X-ray-selected clusters of galaxies from the ROSAT Bright Source Catalog and determine correlation functions for both cluster samples. We find that on small scales the correlation functions depend on the cluster environment: clusters in rich superclusters have a larger correlation length and amplitude than clusters of the whole sample. On large scales the correlation functions depend on the distribution of superclusters, but for both X-ray and Abell clusters they are oscillating with a period of ~115 h-1 Mpc, indicating the presence of a local peak in the power spectrum at an effective wavenumber k=0.055 h Mpc-1.
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CORRELATION AND CLUSTERING Statistical properties of galaxy large scale structures
arXiv (Cornell University), 2001
In this lecture we clarify the basic difference between the correlation properties for systems characterized by small or large fluctuations. The concepts of correlation length, homogeneity scale, scale invariance and criticality are discussed as well. We relate these concepts to the interpretation of galaxy clsutering.
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2000
The UH8K wide field camera of the CFHT was used to image 0.68 deg of sky. From these images, ∼20,000 galaxies were detected to completeness magnitudes V < 23.5 and I < 22.5. The angular correlation function of these galaxies is well represented by the parameterization ω(θ) = AW θ . The slope δ ≃ −0.8 shows no significant variation over the range of magnitude. The amplitude AW decreases with increasing magnitude in a way that is most compatible with a ΛCDM model (Ω0 = 0.2, Λ = 0.8) with a hierarchical clustering evolution parameter ǫ > 0. We infer a best-fit spatial correlation length of r00 ≃ 5.85 ± 0.5 h Mpc at z = 0. The peak redshift of the survey (I ≤ 22.5) is estimated to be zpeak ∼ 0.58, using the blue-evolving luminosity function from the CFRS and the flat Λ cosmology, and r0(zpeak) ≃ 3.5 ± 0.5 h Mpc. We also detect a significant difference in clustering amplitude for the red and blue galaxies, quantitatively measured by correlation lengths of r00 = 5.3 ± 0.5 h Mpc a...
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1993
We propose the zero-point of the cluster-cluster correlation function as a sensitive test for the shape of the power spectrum of initial fluctuations. With a wealth of new available redshifts for rich clusters the correlation function is measured to higher accuracy than has previously been done. In particular it is now possible to go beyond the power law description to measure the point at which the correlation function becomes zero. Four independent measurements of the zero-point of the rich galaxy cluster correlation function indicate that the zero point, r0, should be in the range (40-60)h−1Mpc. The large value of r0 at which the zero-point occurs rules out conventional CDM models independently of the assumed amplitude. The most severe constraints are imposed on the CDM models with the cosmological constant. Models with Ω < 0.25 should be rejected because they predict too large r0. If the age of the Universe is assumed to be larger than 15 Gyr, models with either Ω < 0.5 or...
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