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 Simon C. Reynolds and Pablo de la Cruz and Silvestre Paredes},
  journal={The Astrophysical Journal},
  pages={744 - 755}
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… 

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 complex

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,


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 using

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 numerical

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 is

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 it

0 Statistical Study of the Galaxy Distribution

Large-scale structures in the Universe provide crucial information about formation of structures and can be used to test cosmological models. The good agreement between large-scale observations and

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.

Wavelets, ridgelets and curvelets on the sphere

It is shown how these transforms can be used in denoising and especially in a Combined Filtering Method, which uses both the wavelet and the curvelet transforms, thus benefiting from the advantages of both transforms.

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 galaxies



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 this

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.

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-called

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 Poisson

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 structures

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 is

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 morphological

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 to

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 between

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-point