Three-dimensional Multi-probe Analysis of the Galaxy Cluster A1689

Abstract

We perform a three-dimensional multi-probe analysis of the rich galaxy cluster A1689, one of the most powerful known lenses on the sky, by combining improved weak-lensing data from new wide-field {{BVR}}_Ci\prime z\prime Subaru/Suprime-Cam observations with strong-lensing, X-ray, and Sunyaev-Zel’dovich effect (SZE) data sets. We reconstruct the projected matter distribution from a joint weak-lensing analysis of two-dimensional shear and azimuthally integrated magnification constraints, the combination of which allows us to break the mass-sheet degeneracy. The resulting mass distribution reveals elongation with an axis ratio of ∼0.7 in projection, aligned well with the distributions of cluster galaxies and intracluster gas. When assuming a spherical halo, our full weak-lensing analysis yields a projected halo concentration of {c}_200c^2D=8.9+/- 1.1 ({c}_{vir}^2D∼ 11), consistent with and improved from earlier weak-lensing work. We find excellent consistency between independent weak and strong lensing in the region of overlap. In a parametric triaxial framework, we constrain the intrinsic structure and geometry of the matter and gas distributions, by combining weak/strong lensing and X-ray/SZE data with minimal geometric assumptions. We show that the data favor a triaxial geometry with minor-major axis ratio 0.39±0.15 and major axis closely aligned with the line of sight (22°±10°). We obtain a halo mass {M}_200c=(1.2+/- 0.2)× {10}¹⁵ {M}_⊙ {h}^-1 and a halo concentration {c}_200c=8.4+/- 1.3, which overlaps with the ≳ 1σ tail of the predicted distribution. The shape of the gas is rounder than the underlying matter but quite elongated with minor-major axis ratio 0.60 ± 0.14. The gas mass fraction within 0.9 Mpc is {10}_-2⁺³%, a typical value for high-mass clusters. The thermal gas pressure contributes to ∼60% of the equilibrium pressure, indicating a significant level of non-thermal pressure support. When compared to Planck's hydrostatic mass estimate, our lensing measurements yield a spherical mass ratio of {M}_{\text{}{Planck}}/{M}_{GL}=0.70+/- 0.15 and 0.58 ± 0.10 with and without corrections for lensing projection effects, respectively.

Based in part on data collected at the Subaru Telescope, which is operated by the National Astronomical Society of Japan.