A CMB lensing analysis of the extended mass distribution of clusters

TL;DR

This study uses CMB lensing data to analyze the anisotropic mass distribution of galaxy clusters, revealing their alignment with surrounding large-scale structures and providing insights into cluster mass and shape.

Contribution

It introduces a novel method of stacking CMB lensing maps centered on galaxy clusters to detect anisotropic mass distributions and cluster alignments.

Findings

Significant anisotropic lensing signals up to 40 Mpc/h.

Clusters are aligned with surrounding mass distribution.

Agreement between lensing-based mass estimates and galaxy distribution models.

Abstract

The aim of this work is to study the anisotropic weak lensing signal associated with the mass distribution of massive clusters of galaxies using the Cosmic Microwave Background (CMB) data. For this purpose, we stack patches of the Planck Collaboration 2018 CMB lensing convergence map centered on SDSS DR8 redMaPPer clusters within the redshift range [0.4, 0.5]. We obtain mean radial profiles of the convergence parameter k finding strong signals at scales as large as 40 Mpc/h. By orienting the clusters along their major axis defined through the galaxy member distribution, we find a significant difference between the parallel and perpendicular oriented convergence profiles. The amplitude of the profile along the parallel direction is about 50% larger than that along the perpendicular direction, indicating that the clusters are well aligned with the surrounding mass distribution. From a model with an anisotropic surface mass density, we obtain a suitable agreement for both mass and ellipticities of clusters compared to results derived from weak lensing shear estimates, finding strong evidence of the correlation between the galaxy cluster member distribution and the large--scale mass distribution.