Combining Lens Distortion and Depletion to Map the Mass Distribution of A1689

Understand

[Abridged] We derive a projected 2D mass map of the well studied galaxy cluster A1689 based on an entropy-regularized maximum-likelihood combination of the lens magnification and distortion of red background galaxies registered in deep Subaru images.

• The known strong lensing information is also readily incorporated in this approach, represented as a central pixel with a mean surface density close to the critical value.
• We also utilize the distortion measurements to locally downweight the intrinsic clustering noise, which otherwise perturbs the depletion signal.
• The projected mass profile continuously steepens with radius and is well fitted by the NFW model, but with a surprising large concentration c_vir=13.4^{+5.3}_{-3.3}, lying far from the predicted value of c_vir ~ 5, corresponding to the measured virial mass, M_vir=(2.1\pm 0.2)\times 10^15M_{\odot}, posing a challenge to the standard assumptions defining the LCDM model.