Morphology of the galaxy distribution from wavelet denoising

  title={Morphology of the galaxy distribution from wavelet denoising},
  author={V. J. Mart{\'i}nez and J. L. Starck and E. Saar and David L. Donoho and S. F. Reynolds and Pablo de la Cruz and Silvestre Paredes},
  journal={The Astrophysical Journal},
We have developed a method based on wavelets to obtain the true underlying smooth density from a point distribution. The goal has been to reconstruct the density field in an optimal way, ensuring that the morphology of the reconstructed field reflects the true underlying morphology of the point field, which, as the galaxy distribution, has a genuinely multiscale structure, with near-singular behavior on sheets, filaments, and hot spots. If the discrete distributions are smoothed using Gaussian… Expand
Multiscale morphology of the galaxy distribution
Many statistical methods have been proposed in the last years for analysing the spatial distribution of galaxies. Very few of them, however, can handle properly the border effects of complexExpand
The Multiscale Morphology Filter: Identifying and Extracting Spatial Patterns in the Galaxy Distribution
Aims. We present here a new method, MMF, for automatically segmenting cosmic structure into its basic components: clusters, fi laments, and walls. Importantly, the segmentation is scale independent,Expand
Topology of non-linear structure in the 2dF Galaxy Redshift Survey
We study the evolution of non-linear structure as a function of scale in samples from the 2dF Galaxy Redshift Survey, constituting over 221 000 galaxies at a median redshift of z = 0.11. The twoExpand
Structure in the Three-dimensional Galaxy Distribution. I. Methods and Example Results
Three methods for detecting and characterizing structure in point data, such as that generated by redshift surveys, are described: classification using self-organizing maps, segmentation usingExpand
Wavelet analysis of the cosmic web formation
According to the modern cosmological paradigm galaxies and galaxy systems form from tiny density perturbations generated during the very early phase of the evolution of the Universe. Using numericalExpand
Structural analysis of the SDSS Cosmic Web – I. Non-linear density field reconstructions
This study is the first in a series in which we analyse the structure and topology of the Cosmic Web as traced by the Sloan Digital Sky Survey (SDSS). The main issue addressed in the present study isExpand
Discriminating topology in galaxy distributions using network analysis
(abridged) The large-scale distribution of galaxies is generally analyzed using the two-point correlation function. However, this statistic does not capture the topology of the distribution, and itExpand
Geometry and Morphology of the Cosmic Web: Analyzing Spatial Patterns in the Universe
The Watershed Voidfinder (WVF), which invokes the discrete watershed transform to identify voids in the cosmic matter distribution, is discussed, which is able to determine the location, size and shape of the voids. Expand
Wavelets, ridgelets and curvelets on the sphere
We present in this paper new multiscale transforms on the sphere, namely the isotropic undecimated wavelet transform, the pyramidal wavelet transform, the ridgelet transform and the curveletExpand
Topology of large-scale structure in the 2dF Galaxy Redshift Survey
We investigate the topology of the completed 2dF Galaxy Redshift Survey (2dFGRS), drawing two flux-limited samples of the local Universe from the 2dFGRS catalogue, which contains over 220000 galaxiesExpand


Wavelet analysis of the multifractal character of the galaxy distribution
We have determined generalized dimensions of the observed distribution of galaxies. Their different values indicate that this distribution may be described as a multifractal. In order to analyse thisExpand
Analysis of the Spatial Distribution of Galaxies by Multiscale Methods
It is shown that statistical properties of transform coefficients measure in a coherent and statistically reliable way, the degree of clustering, filamentarity, sheetedness, and voidedness of a data set. Expand
Nonparametric Estimation of Intensity Maps Using Haar Wavelets and Poisson Noise Characteristics
We present a method for the nonparametric (model-free) estimation of an intensity map underlying two-dimensional count data with Poisson noise characteristics. Specifically, we extend the so-calledExpand
Structure Detection in Low Intensity X-Ray Images using the Wavelet Transfor M Applied to Galaxy Cluster Cores Analysis
In the context of assessing and characterizing structures in X-ray images, we compare different approaches. Most often the intensity level is very low and necessitates a special treatment of PoissonExpand
Objective Detection of Voids and High-Density Structures in the First CfA Redshift Survey Slice
Voids of galaxies delineated by sharp one- or two-dimensional structures are the main features of the large-scale clustering of galaxies. In order to objectively identify the significant structuresExpand
The topology of the large-scale structure of the universe
It has been suggested recently that the topology of a distribution of galaxies can be characterized by the mean Gaussian curvature per unit volume of surfaces of constant density. An expression isExpand
Beyond Genus Statistics: A Unifying Approach to the Morphology of Cosmic Structure
The genus statistics of isodensity contours has become a well-established tool in cosmology. In this Letter we place the genus in the wider framework of a complete family of morphologicalExpand
The 2dF Galaxy Redshift Survey : higher-order galaxy correlation functions
We measure moments of the galaxy count probability distribution function in the Two-degree Field Galaxy Redshift Survey (2dFGRS). The survey is divided into volume-limited subsamples in order toExpand
Quantifying the topology of large-scale structure
We propose and investigate a new algorithm for quantifying the topological properties of cosmological density fluctuations. We first motivate this algorithm by drawing a formal distinction betweenExpand
The 2dF Galaxy Redshift Survey: hierarchical galaxy clustering
We use the Two-Degree Field Galaxy Redshift Survey (2dFGRS) to test the hierarchical scaling hypothesis: namely, that the p-point galaxy correlation functions can be written in terms of the two-pointExpand