Weak Lensing Mass Reconstruction: Flexion vs Shear

Abstract

Weak gravitational lensing has proven to be a powerful tool to map directly the distribution of dark matter in the Universe. The technique, currently used, relies on the accurate measurement of the gravitational shear that corresponds to the first-order distortion of the background galaxy images. More recently, a new technique has been introduced that relies on the accurate measurement of the gravitational flexion that corresponds to the second-order distortion of the background galaxy images. This technique should probe structures on smaller scales than that of a shear analysis. The goal of this paper is to compare the ability of shear and flexion to reconstruct the dark matter distribution by taking into account the dispersion in shear and flexion measurements. Our results show that the flexion is less sensitive than shear for constructing the convergence maps on scales that are physically feasible for mapping, meaning that flexion alone not be used to do convergence map reconstruction, even on small scales.

Submitted to ApJ

References in corpus (4)

• Delensing Gravitational Wave Standard Sirens with Shear and Flexion Maps
• Weak gravitational shear and flexion with polar shapelets
• A Method for Weak Lensing Flexion Analysis by the HOLICs Moment Approach
• Detecting Mass Substructure in Galaxy Clusters: An Aperture Mass Statistic for Gravitational Flexion

Cited by in corpus (7)

• Cosmology and Fundamental Physics with the Euclid Satellite
• Cosmology and fundamental physics with the Euclid satellite
• Cosmology with cosmic shear observations: a review
• Internal Cluster Structure
• Constraining primordial non-Gaussianity with cosmological weak lensing: shear and flexion
• Probe combination in large galaxy surveys : Application of Fisher information and Shannon entropy to weak lensing
• The general theory of secondary weak gravitational lensing