Mass Calibration of Galaxy Clusters at Redshift 0.1-1.0 using Weak Lensing in the Sloan Digital Sky Survey Stripe 82 Co-add

Abstract

We present galaxy cluster mass-richness relations found in the Sloan Digital Sky Survey Stripe 82 co-add using clusters found using a Voronoi tessellation cluster finder. These relations were found using stacked weak lensing shear observed in a large sample of galaxy clusters. These mass-richness relations are presented for four redshift bins, $0.1 < z \leq 0.4$, $0.4 < z \leq 0.7$, $0.7 < z \leq 1.0$ and $0.1 < z \leq 1.0$. We describe the sample of galaxy clusters and explain how these clusters were found using a Voronoi tessellation cluster finder. We fit an NFW profile to the stacked weak lensing shear signal in redshift and richness bins in order to measure virial mass $(M_{200})$. We describe several effects that can bias weak lensing measurements, including photometric redshift bias, the effect of the central BCG, halo miscentering, photometric redshift uncertainty and foreground galaxy contamination. We present mass-richness relations using richness measure $N_{VT}$ with each of these effects considered separately as well as considered altogether. We also examine redshift evolution of the mass-richness relation. As a result we present measurements of the mass coefficient ($M_{200|20}$) and the power law slope ($\alpha$) for power law fits to the mass and richness values in each of the redshift bins. We find values of the mass coefficient of $8.49 \pm 0.526$, $14.1 \pm 1.78$, $30.2 \pm 8.74$ and $9.23 \pm 0.525 \times 10^{13}$ $h^{-1}$ $M_{sun}$ for each of the four redshift bins respectively. We find values of the power law slope of $0.905 \pm 0.0585$, $0.948 \pm 0.100$, $1.33 \pm 0.260$ and $0.883 \pm 0.0500$ respectively.