RCSLenS: A new estimator for large-scale galaxy-matter correlations

TL;DR

This paper introduces a new statistical estimator for analyzing large-scale galaxy-matter correlations, improving measurement accuracy and data compression for cosmological studies.

Contribution

The paper presents a novel estimator for galaxy-matter correlations and demonstrates its application to galaxy bias and cross-correlation measurements using weak lensing data.

Findings

Higher galaxy bias and cross-correlation coefficient than previous reports.

First application of a complete set of discrete estimators for galaxy-galaxy lensing.

Method enhances data compression for joint weak lensing and galaxy clustering analysis.

Abstract

We present measurements of the galaxy bias $b$ and the galaxy-matter cross-correlation coefficient $r$ for the BOSS LOWZ luminous red galaxy sample. Using a new statistical weak lensing analysis of the Red Sequence Cluster Lensing Survey (RCSLenS) we find the bias properties of this sample to be higher than previously reported with $b=2.45^{+0.05}_{-0.05}$ and $r=1.64^{+0.17}_{-0.16}$ on scales between $3'$ and $20'$. We repeat the measurement for angular scales of $20'\leq \vartheta \leq70'$, which yields $b=2.39^{+0.07}_{-0.07}$ and $r=1.24^{+0.26}_{-0.25}$. This is the first application of a data compression analysis using a complete set of discrete estimators for galaxy-galaxy lensing and galaxy clustering. As cosmological data sets grow, our new method of data compression will become increasingly important in order to interpret joint weak lensing and galaxy clustering measurements and to estimate the data covariance. In future studies this formalism can be used as a tool to study the large-scale structure of the Universe to yield a precise determination of cosmological parameters.