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Title: INTERPRETING THE DISTANCE CORRELATION RESULTS FOR THE COMBO-17 SURVEY

The accurate classification of galaxies in large-sample astrophysical databases of galaxy clusters depends sensitively on the ability to distinguish between morphological types, especially at higher redshifts. This capability can be enhanced through a new statistical measure of association and correlation, called the distance correlation coefficient, which has more statistical power to detect associations than does the classical Pearson measure of linear relationships between two variables. The distance correlation measure offers a more precise alternative to the classical measure since it is capable of detecting nonlinear relationships that may appear in astrophysical applications. We showed recently that the comparison between the distance and Pearson correlation coefficients can be used effectively to isolate potential outliers in various galaxy data sets, and this comparison has the ability to confirm the level of accuracy associated with the data. In this work, we elucidate the advantages of distance correlation when applied to large databases. We illustrate how the distance correlation measure can be used effectively as a tool to confirm nonlinear relationships between various variables in the COMBO-17 database, including the lengths of the major and minor axes, and the alternative redshift distribution. For these outlier pairs, the distance correlation coefficient is routinely higher thanmore » the Pearson coefficient since it is easier to detect nonlinear relationships with distance correlation. The V-shaped scatter plots of Pearson versus distance correlation coefficients also reveal the patterns with increasing redshift and the contributions of different galaxy types within each redshift range.« less
Authors:
 [1] ;  [2] ;  [3]
  1. Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)
  2. Institut für Angewandte Mathematik, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 294, D-69120 Heidelberg (Germany)
  3. Department of Statistics, Instituto Tecnológico Autónomo de México, Del. Álvaro Obregón, 04510, México D. F. (Mexico)
Publication Date:
OSTI Identifier:
22365929
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 784; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; CLASSIFICATION; COMPARATIVE EVALUATIONS; CORRELATIONS; DISTANCE; GALACTIC EVOLUTION; GALAXIES; GALAXY CLUSTERS; NONLINEAR PROBLEMS; POTENTIALS; RED SHIFT; STATISTICS