Weak-lensing mass calibration of redMaPPer galaxy clusters in Dark Energy Survey Science Verification data

Abstract

We use weak-lensing shear measurements to determine the mean mass of optically selected galaxy clusters in Dark Energy Survey Science Verification data. In a blinded analysis, we split the sample of more than 8,000 redMaPPer clusters into 15 subsets, spanning ranges in the richness parameter $5\le \hat{I}»\le 180$ and redshift $0.2\le z\le 0.8$, and fit the averaged mass density contrast profiles with a model that accounts for seven distinct sources of systematic uncertainty: shear measurement and photometric redshift errors; cluster-member contamination; miscentering; deviations from the NFW halo profile; halo triaxiality; and line-of-sight projections. We combine the inferred cluster masses to estimate the joint scaling relation between mass, richness and redshift, $\mathcal{M}(\hat{I}»,z)\propto M_0\hat{I}{»}^F(1+z{)}^G$. We find $M_0\equiv ⟨M_{200\mathrm{m}}|\hat{I}»=30,z=0.5⟩=\left[2.35\pm 0.22(\mathrm{stat})\pm 0.12(\mathrm{sys})\right]\cdot 10^{14}{M}_{\odot }$, with $F=1.12\pm 0.20(\mathrm{stat})\pm 0.06(\mathrm{sys})$ and $G=0.18\pm 0.75(\mathrm{stat})\pm 0.24(\mathrm{sys})$. The amplitude of the mass-richness relation is in excellent agreement with the weak-lensing calibration of redMaPPer clusters in SDSS by Simet et al. (2016) and with the Saro et al. (2015) calibration based on abundance matching of SPT-detected clusters. Our results extend the redshift range over which the mass-richness relation of redMaPPer clusters has been calibrated with weak lensing from $z\le 0.3$ to $z\le 0.8$. Calibration uncertainties of shear measurements and photometric redshift estimates dominate our systematic error budget and require substantial improvements for forthcoming studies.

22 pages, 14 figures, accepted by MNRAS