μ⋆ masses: weak-lensing calibration of the Dark Energy Survey Year 1 redMaPPer clusters using stellar masses
Abstract
We present the weak-lensing mass calibration of the stellar-mass-based μ⋆ mass proxy for redMaPPer galaxy clusters in the Dark Energy Survey Year 1. For the first time, we are able to perform a calibration of μ⋆ at high redshifts, z > 0.33. In a blinded analysis, we use ~6000 clusters split into 12 subsets spanning the ranges 0.1 ≤ z < 0.65 and μ⋆ up to ${\sim} 5.5 \times 10^{13} \, \mathrm{M}_{\odot }$, and infer the average masses of these subsets through modelling of their stacked weak-lensing signal. In our model, we account for the following sources of systematic uncertainty: shear measurement and photometric redshift errors, miscentring, cluster-member contamination of the source sample, deviations from the Navarro-Frenk-White halo profile, halo triaxiality, and projection effects. We use the inferred masses to estimate the joint mass-μ⋆-z scaling relation given by $\langle M_{200c} | \mu _{\star },z \rangle = M_0 (\mu _{\star }/5.16\times 10^{12} \, \mathrm{M_{\odot }})^{F_{\mu _{\star }}} ((1+z)/1.35)^{G_z}$. We find $M_0= (1.14 \pm 0.07) \times 10^{14} \, \mathrm{M_{\odot }}$ with $F_{\mu _{\star }}= 0.76 \pm 0.06$ and Gz = -1.14 ± 0.37. We discuss the use of μ⋆ as a complementary mass proxy to the well-studied richness λ for: (i) exploring the regimes of low z, λ < 20 and high λ, z ~ 1; and (ii) testing systematics such as projection effects for applications in cluster cosmology.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 2020
- DOI:
- 10.1093/mnras/staa2687
- arXiv:
- arXiv:2006.10162
- Bibcode:
- 2020MNRAS.498.5450P
- Keywords:
-
- gravitational lensing: weak;
- galaxies: clusters: general;
- cosmology: observations;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 20 pages, 10 figures, submitted to MNRAS