THREE-DIMENSIONAL MULTI-PROBE ANALYSIS OF THE GALAXY CLUSTER A1689

Umetsu Keiichi

Sereno Mauro

Medezinski Elinor

Nonino Mario

Mroczkowski Tony

Diego Jose M.

Ettori Stefano

Okabe Nobuhiro

Broadhurst Tom

Lemze Doron

The Astrophysical Journal

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 BVRCi'z' 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 weaklensing analysis yields a projected halo concentration of c^2D_200c = 8.9 ± 1.1 (c^2D_vir ~ 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 Mʘ 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 0.9Mpc is 10 ^+3_-2 %, 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 Planckʼs hydrostatic mass estimate, our lensing measurements yield a spherical mass ratio of M_Planck / M_GL = 0.70 ± 0.15 and 0.58 ± 0.10 with and without corrections for lensing projection effects, respectively.

cosmology: observations – dark matter – galaxies: clusters: individual (A1689) – gravitational lensing: strong – gravitational lensing: weak

天文学・宇宙科学 [ 440 ]

英語

IOP Publishing

© 2015. The American Astronomical Society. All rights reserved.

[ISSN] 0004-637X

[ISSN] 1538-4357

[NCID] AA00553253

[DOI] 10.1088/0004-637X/806/2/207

[DOI] https://doi.org/10.1088/0004-637X/806/2/207