A Multi-Resolution Weak Lensing Mass Reconstruction Method

TL;DR

This paper introduces a multi-resolution maximum-likelihood method for reconstructing two-dimensional mass maps from weak gravitational lensing data, improving resolution and sub-structure detection in high-distortion regions.

Contribution

The paper presents a novel multi-resolution approach that enhances mass map detail and sub-structure analysis compared to traditional methods.

Findings

Effective in producing high-resolution mass maps in regions with strong distortions

Improves detection of sub-structures within galaxy clusters

Validated on simulated and real survey data

Abstract

Motivated by the limitations encountered with the commonly used direct reconstruction techniques of producing mass maps, we have developed a multi-resolution maximum-likelihood reconstruction method for producing two dimensional mass maps using weak gravitational lensing data. To utilize all the shear information, we employ an iterative inverse method with a properly selected regularization coefficient which fits the deflection potential at the position of each galaxy. By producing mass maps with multiple resolutions in the different parts of the observed field, we can achieve a comparable level of signal to noise by increasing the resolution in regions of higher distortions or regions with an over-density of background galaxies. In addition, we are able to better study the sub-structure of the massive clusters at a resolution which is not attainable in the rest of the observed field. We apply our method to the simulated data and to a four square degree field obtained by the Deep Lens Survey.