Mass Modeling of Abell 1689 Advanced Camera for Surveys Observations with a Perturbed Navarro‐Frenk‐White Model

Abstract

The combined resolution and sensitivity of the Advanced Camera for Surveys deep imaging provides the capability of high-accuracy lens modeling of Abell 1689. Originally based on the technique of Broadhurst and coworkers, our software is designed to provide a precise and efficient method of modeling cluster lenses without assumptions relating the large-scale cluster dark matter to the light. Abell 1689 is robustly modeled using a freely varying cluster halo component consisting of an NFW profile, shapelets (Refregier), and a mass sheet, as well as a galaxy component based on the light. Another improvement over previous modeling techniques is the application of magnification-corrected image magnitude constraints. The mass within the ~50" Einstein radius was found to be 2.04+0.03-0.11×1014 Msolar and was reliably fitted by an NFW with c=r200/rs=5.70+0.34-0.50 and rs=239+28-24 arcsec (727+85-73 kpc), which gives dlnρ/dlnr=-1.34 at r=150 kpc. The overall B-band mass-to-light ratio within the Einstein radius is 215+13-2 Msolar L-1solar versus only 32+3-1 Msolar L-1solar for the galaxy component. For the overall surface mass density distribution, there are two regimes where the slope, dlogΣ/dlogR, is nearly constant. The intermediate slope from 6 to 30 kpc is -0.41+0.01-0.05, while the outer slope from 80 to 120 kpc is -0.57+0.02-0.12. In addition, our final model is consistent with the results from Broadhurst and coworkers. Monte Carlo simulations are also performed to explore the modeling systematics related to the image positional errors, the dependence on multiple image systems, and the WMAP predictions.