文章基本信息

标题：Enhanced cluster lensing models with measured galaxy kinematics
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作者：P. Bergamini ; P. Rosati ; A. Mercurio 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2019
卷号：631
页码：1-16
DOI：10.1051/0004-6361/201935974
语种：English
出版社：EDP Sciences
摘要：We present an improved determination of the total mass distribution of three massive clusters from the Cluster Lensing and Supernova Survey withHubbleandHubbleFrontier Fields, MACS J1206.2−0847 (z = 0.44), MACS J0416.1−2403 (z = 0.40), Abell S1063 (z = 0.35). We specifically reconstructed the sub-halo mass component with robust stellar kinematics information of cluster galaxies, in combination with precise strong lensing models based on large samples of spectroscopically identified multiple images. We used integral-field spectroscopy in the cluster cores, from the Multi Unit Spectroscopic Explorer on the Very Large Telescope, to measure the stellar velocity dispersion,σ, of 40−60 member galaxies per cluster, covering four to five magnitudes tomF160W ≃ 21.5. We verified the robustness and quantified the accuracy of the velocity dispersion measurements with extensive spectral simulations. With these data, we determined the normalization and slope of the galaxyL–σFaber–Jackson relation in each cluster and used these parameters as a prior for the scaling relations of the sub-halo population in the mass distribution modeling. When compared to our previous lens models, the inclusion of member galaxies’ kinematics provides a similar precision in reproducing the positions of the multiple images. However, the inherent degeneracy between the central effective velocity dispersion,σ0, and truncation radius,rcut, of sub-halos is strongly reduced, thus significantly alleviating possible systematics in the measurements of sub-halo masses. The three independent determinations of theσ0 − rcutscaling relation in each cluster are found to be fully consistent, enabling a statistical determination of sub-halo sizes as a function ofσ0, or halo masses. Finally, we derived the galaxy central velocity dispersion functions of the three clusters projected within 16% of their virial radius, finding that they are well in agreement with each other. We argue that such a methodology, when applied to high-quality kinematics and strong lensing data, allows the sub-halo mass functions to be determined and compared with those obtained from cosmological simulations.
关键词：engravitational lensing: stronggalaxies: clusters: generalcosmology: observationsdark mattergalaxies: kinematics and dynamics