English

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

Cosmology and Nongalactic Astrophysics 2015-07-03 v2

Abstract

We perform a 3D multi-probe analysis of the rich galaxy cluster A1689 by combining improved weak-lensing data from new BVRi'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 2D 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 axis ratio ~0.7 in projection. When assuming a spherical halo, our full weak-lensing analysis yields a projected concentration of c200c2D=8.9±1.1c_{200c}^{2D}=8.9\pm 1.1 (cvir2D11c_{vir}^{2D}\sim 11), consistent with and improved from earlier weak-lensing work. We find excellent consistency between 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 deg). We obtain M200c=(1.2±0.2)×1015M/hM_{200c}=(1.2\pm 0.2)\times 10^{15} M_{\odot}/h and c200c=8.4±1.3c_{200c}=8.4\pm 1.3, which overlaps with the >1σ>1\sigma 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}%. 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 MPlanck/MGL=0.70±0.15M_{Planck}/M_{GL}=0.70\pm 0.15 and 0.58±0.100.58\pm 0.10 with and without corrections for lensing projection effects, respectively.

Keywords

Cite

@article{arxiv.1503.01482,
  title  = {Three-dimensional Multi-probe Analysis of the Galaxy Cluster A1689},
  author = {Keiichi Umetsu and Mauro Sereno and Elinor Medezinski and Mario Nonino and Tony Mroczkowski and Jose M. Diego and Stefano Ettori and Nobuhiro Okabe and Tom Broadhurst and Doron Lemze},
  journal= {arXiv preprint arXiv:1503.01482},
  year   = {2015}
}

Comments

Accepted by ApJ. Minor textual changes to improve clarity (e.g., 5. HST STRONG-LENSING ANALYSIS). 26 pages, 17 figures. A version with high-resolution figures is available at http://www.asiaa.sinica.edu.tw/~keiichi/upfiles/Umetsu15/umetsu15.pdf

R2 v1 2026-06-22T08:44:43.058Z