The Canadian Cluster Comparison Project: detailed study of systematics and updated weak lensing masses

TL;DR

This study revisits weak lensing mass measurements of 50 galaxy clusters, thoroughly analyzing systematic errors, updating mass estimates, and assessing the hydrostatic mass bias in relation to Planck CMB data.

Contribution

It provides an updated, systematic analysis of cluster masses with improved calibration and redshift estimates, and evaluates the hydrostatic bias in the context of cosmological tensions.

Findings

Updated cluster masses with reduced uncertainties

Quantified the dominant systematic error from photometric redshifts

Estimated hydrostatic mass bias as 1-b=0.76±0.05(stat)±0.06(syst)

Abstract

Masses of clusters of galaxies from weak gravitational lensing analyses of ever larger samples are increasingly used as the reference to which baryonic scaling relations are compared. In this paper we revisit the analysis of a sample of 50 clusters studied as part of the Canadian Cluster Comparison Project. We examine the key sources of systematic error in cluster masses. We quantify the robustness of our shape measurements and calibrate our algorithm empirically using extensive image simulations. The source redshift distribution is revised using the latest state-of-the-art photometric redshift catalogs that include new deep near-infrared observations. Nonetheless we find that the uncertainty in the determination of photometric redshifts is the largest source of systematic error for our mass estimates. We use our updated masses to determine b, the bias in the hydrostatic mass, for the clusters detected by Planck. Our results suggest 1-b=0.76+-0.05(stat)}+-0.06(syst)}, which does not resolve the tension with the measurements from the primary cosmic microwave background.