Evolution of hierarchical clustering in the CFHTLS-Wide since z~1

TL;DR

This study measures higher order galaxy clustering in the CFHTLS-Wide survey across redshifts 0.2 to 1, revealing scale-dependent evolution consistent with LambdaCDM predictions and suggesting increased non-linear clustering at higher redshifts.

Contribution

It provides the first detailed measurements of higher order galaxy clustering evolution over a wide redshift range using CFHTLS data, testing theoretical models.

Findings

Hierarchical moments increase with redshift at small scales.

Measurements agree with perturbation theory at large scales.

Field-to-field scatter matches analytical predictions.

Abstract

We present measurements of higher order clustering of galaxies from the latest release of the Canada-France-Hawaii-Telescope Legacy Survey (CFHTLS) Wide. We construct a volume-limited sample of galaxies that contains more than one million galaxies in the redshift range 0.2<z<1 distributed over the four independent fields of the CFHTLS. We use a counts in cells technique to measure the variance <xi_2> and the hierarchical moments S_n = <xi_n>/<xi_2>^(n-1) (3<n<5) as a function of redshift and angular scale.The robustness of our measurements if thoroughly tested, and the field-to-field scatter is in very good agreement with analytical predictions. At small scales, corresponding to the highly non-linear regime, we find a suggestion that the hierarchical moments increase with redshift. At large scales, corresponding to the weakly non-linear regime, measurements are fully consistent with perturbation theory predictions for standard LambdaCDM cosmology with a simple linear bias.