<i>HUBBLE SPACE TELESCOPE</i>COMBINED STRONG AND WEAK LENSING ANALYSIS OF THE CLASH SAMPLE: MASS AND MAGNIFICATION MODELS AND SYSTEMATIC UNCERTAINTIES

Abstract

We present results from a comprehensive lensing analysis in HST data, of the\ncomplete CLASH cluster sample. We identify new multiple-images previously\nundiscovered allowing improved or first constraints on the cluster inner mass\ndistributions and profiles. We combine these strong-lensing constraints with\nweak-lensing shape measurements within the HST FOV to jointly constrain the\nmass distributions. The analysis is performed in two different common\nparameterizations (one adopts light-traces-mass for both galaxies and dark\nmatter while the other adopts an analytical, elliptical NFW form for the dark\nmatter), to provide a better assessment of the underlying systematics - which\nis most important for deep, cluster-lensing surveys, especially when studying\nmagnified high-redshift objects. We find that the typical (median), relative\nsystematic differences throughout the central FOV are $\\sim40\\%$ in the\n(dimensionless) mass density, $\\kappa$, and $\\sim20\\%$ in the magnification,\n$\\mu$. We show maps of these differences for each cluster, as well as the mass\ndistributions, critical curves, and 2D integrated mass profiles. For the\nEinstein radii ($z_{s}=2$) we find that all typically agree within $10\\%$\nbetween the two models, and Einstein masses agree, typically, within\n$\\sim15\\%$. At larger radii, the total projected, 2D integrated mass profiles\nof the two models, within $r\\sim2\\arcmin$, differ by $\\sim30\\%$. Stacking the\nsurface-density profiles of the sample from the two methods together, we obtain\nan average slope of $d\\log (\\Sigma)/d\\log(r)\\sim-0.64\\pm0.1$, in the radial\nrange [5,350] kpc. Lastly, we also characterize the behavior of the average\nmagnification, surface density, and shear differences between the two models,\nas a function of both the radius from the center, and the best-fit values of\nthese quantities.\n