Redshift distortions of galaxy correlation functions
- Fermi National Accelerator Lab., Batavia, IL (United States)
To examine how peculiar velocities can affect the 2-, 3-, and 4-point correlation functions, we evaluate volume-average correlations for configurations that emphasize and minimize distortions for four different volume-limited samples from each of the CfA, SSRS, and IRAS redshift catalogs. We present the results as the correlation length r{sub 0} and power index {gamma} of the 2-point correlation, {anti {Xi}}{sub 2} = (r{sub 0}/r){sup {gamma}}, and as the hierarchical amplitudes of the 3- and 4-point functions, S{sub 3} = {anti {Xi}}{sub 3}/{anti {Xi}}{sub 2}{sup 2} and S{sub 4} = {anti {Xi}}/{anti {Xi}}{sub 2}{sup 3}. We find a characteristic distortion for {anti {Xi}}{sub 2}: The slope {gamma} is flatter and the correlation length is larger in redshift space than in real space; that is, redshift distortions ``move`` correlations from small to large scales. At the largest scales, extra power in the redshift distribution is compatible with {Omega}{sup 4/7}/b {approx} 1; we find 0.53 {plus_minus} 0.15, 1.10 {plus_minus} 0.16 and 0.84 {plus_minus} 0.45 for the CfA, SSRS and IRAS catalogs. Higher order correlations {anti {Xi}}{sub 3} and {anti {Xi}}{sub 4} suffer similar redshift distortions, but in such a way that, within the accuracy of our analysis, the normalized amplitudes S{sub 3} and S{sub 4} are insensitive to this effect. The hierarchical amplitudes S{sub 3} and S{sub 4} are constant as a function of scale between 1-12 h{sup {minus}1} Mpc and have similar values in all samples and catalogues, S{sub 3} {approx} 2 and S{sub 4} {approx} 6, despite the fact that {anti {Xi}}{sub 2}, {anti {Xi}}{sub 3}, and {anti {Xi}}{sub 4} differ from one sample to another by large factors. The agreement between the independent estimations of S{sub 3} and S{sub 4} is remarkable given the different criteria in the selection of galaxies and also the difference in the resulting range of densities, luminosities and locations between samples.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States); National Aeronautics and Space Administration, Washington, DC (United States)
- DOE Contract Number:
- AC02-76CH03000
- OSTI ID:
- 10160622
- Report Number(s):
- FNAL/Pub-93-097-A; ON: DE93014007; CNN: Grant NAGW-2381
- Resource Relation:
- Other Information: PBD: 12 May 1993
- Country of Publication:
- United States
- Language:
- English
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