Details

Autor(en) / Beteiligte

• Chiu, I-Non
• Umetsu, Keiichi
• Sereno, Mauro
• Ettori, Stefano
• Meneghetti, Massimo
• Merten, Julian
• Sayers, Jack
• Zitrin, Adi

Titel

CLUMP-3D: Three-dimensional Shape and Structure of 20 CLASH Galaxy Clusters from Combined Weak and Strong Lensing

Ist Teil von

• The Astrophysical journal, 2018-06, Vol.860 (2), p.126

Ort / Verlag

Philadelphia: The American Astronomical Society

Erscheinungsjahr

2018

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• We perform a three-dimensional triaxial analysis of 16 X-ray regular and 4 high-magnification galaxy clusters selected from the CLASH survey by combining two-dimensional weak-lensing and central strong-lensing constraints. In a Bayesian framework, we constrain the intrinsic structure and geometry of each individual cluster assuming a triaxial Navarro-Frenk-White halo with arbitrary orientations, characterized by the mass , halo concentration , and triaxial axis ratios ( ), and investigate scaling relations between these halo structural parameters. From triaxial modeling of the X-ray-selected subsample, we find that the halo concentration decreases with increasing cluster mass, with a mean concentration of at the pivot mass . This is consistent with the result from spherical modeling, . Independently of the priors, the minor-to-major axis ratio of our full sample exhibits a clear deviation from the spherical configuration ( at with uniform priors), with a weak dependence on the cluster mass. Combining all 20 clusters, we obtain a joint ensemble constraint on the minor-to-major axis ratio of and a lower bound on the intermediate-to-major axis ratio of at the 2 level from an analysis with uniform priors. Assuming priors on the axis ratios derived from numerical simulations, we constrain the degree of triaxiality for the full sample to be at , indicating a preference for a prolate geometry of cluster halos. We find no statistical evidence for an orientation bias ( ), which is insensitive to the priors and in agreement with the theoretical expectation for the CLASH clusters.