Bias and HighOrder Galaxy Correlation Functions in the APM Galaxy Survey
Abstract
On large scales, the higher order moments of the mass distribution, S_J_ = ξ^bar^_J_/ξ^bar^_2_^J1^, e.g., the skewness S_3_ and kurtosis S_4_, can be predicted using nonlinear perturbation theory. Comparison of these predictions with moments of the observed galaxy distribution probes the bias between galaxies and mass. Applying this method to models with initially Gaussian fluctuations and power spectra P(k) similar to that of galaxies in the Automatic Plate Measuring (APM) survey, we find that the predicted higher order moments S_J_(R) are in good agreement with those directly inferred from the APM survey in the absence of bias. We use this result to place limits on the linear and nonlinear bias parameters. Models in which the extra power observed on large scales (with respect to the standard cold dark matter [CDM] model) is produced by scaledependent bias match the APM higher order amplitudes only if nonlinear bias (rather than nonlinear gravity) generates the observed higher order moments. When normalized to COBE DMR, these models are significantly ruled out by the S_J_ observations. The cold plus hot dark matter model normalized to COBE can reproduce the APM higher order correlations if one introduces nonlinear bias terms, while the low density CDM model with a cosmological constant does not require any bias to fit the largescale amplitudes.
 Publication:

The Astrophysical Journal
 Pub Date:
 December 1994
 DOI:
 10.1086/187671
 arXiv:
 arXiv:astroph/9407079
 Bibcode:
 1994ApJ...437L..13G
 Keywords:

 Bias;
 Galactic Clusters;
 Kurtosis;
 Mass Distribution;
 Nonlinearity;
 Perturbation Theory;
 Skewness;
 Astronomical Models;
 Cosmic Background Explorer Satellite;
 Dark Matter;
 Power Spectra;
 Sky Surveys (Astronomy);
 Astrophysics;
 COSMOLOGY: LARGESCALE STRUCTURE OF UNIVERSE;
 GALAXIES: CLUSTERING;
 Astrophysics
 EPrint:
 8 pages, 2 figures included, uuencoded postscript file (100 kB), FermilabPub94/207A