Higher-Order Angular Galaxy Correlations in the SDSS: Redshift and Color Dependence of non-Linear Bias
Abstract
We present estimates of the N-point galaxy, area-averaged, angular correlation functions () for = 2,...,7 for galaxies from the fifth data release of the Sloan Digital Sky Survey. Our parent sample is selected from galaxies with , and is the largest ever used to study higher-order correlations. We subdivide this parent sample into two volume limited samples using photometric redshifts, and these two samples are further subdivided by magnitude, redshift, and color (producing early- and late-type galaxy samples) to determine the dependence of () on luminosity, redshift, and galaxy-type. We measure () using oversampling techniques and use them to calculate the projected, . Using models derived from theoretical power-spectra and perturbation theory, we measure the bias parameters and , finding that the large differences in both bias parameters ( and ) between early- and late-type galaxies are robust against changes in redshift, luminosity, and , and that both terms are consistently smaller for late-type galaxies. By directly comparing their higher-order correlation measurements, we find large differences in the clustering of late-type galaxies at redshifts lower than 0.3 and those at redshifts higher than 0.3, both at large scales ( is larger by at ) and small scales (large amplitudes are measured at small scales only for , suggesting much more merger driven star formation at ). Finally, our measurements of suggest both that and is negative.
Cite
@article{arxiv.0704.2573,
title = {Higher-Order Angular Galaxy Correlations in the SDSS: Redshift and Color Dependence of non-Linear Bias},
author = {Ashley J. Ross and Robert J. Brunner and Adam D. Myers},
journal= {arXiv preprint arXiv:0704.2573},
year = {2009}
}
Comments
46 pages, 19 figures, Accepted to ApJ