Oral Presentation
Mass Distribution in and around Galaxy Clusters from Weak Lensing Shear and Magnification
Presenter: Keiichi Umetsu (ASIAA)
Galaxy clusters play a fundamental role in testing models of cosmic structure formation and constraining the properties of dark matter (DM). In this talk, I will present recent results from Umetsu et al. 2014 (arXiv:1404.1375), who performed a joint weak-lensing shear-and-magnification analysis of 16 X-ray-regular and 4 high-magnification clusters selected from the CLASH survey. From a stacked shear-only analysis of the X-ray-selected subsample, we show the stacked lensing signal is well described by a family of standard density pro files predicted for DM-dominated halos, including the Navarro-Frenk-White and Einasto models. We show our stacked constraint on the halo concentration is in excellent agreement with CDM predictions when the CLASH X-ray selection function and projection effects are taken into account. We reconstruct projected mass density profiles of all CLASH clusters from a joint likelihood analysis of shear-and-magnification data, and measure cluster masses at several characteristic radii. We also derive an ensemble-averaged total projected mass profile of the X-ray-selected subsample by stacking their individual mass pro files. The stacked total mass profile is shown to be consistent with our shear-based halo-model predictions including the effects of surrounding large-scale structure as a two-halo term, establishing further consistency in the context of the CDM model.
asiaa.sinica.edu.tw