The SDSS Coadd: Cross-Correlation Weak Lensing and Tomography of Galaxy Clusters

TL;DR

This paper utilizes the SDSS coadded data in Stripe 82 to analyze weak lensing effects on galaxy clusters, introducing a new tomographic parameterization that enhances detection and allows for cluster mass profile constraints.

Contribution

It presents a novel parameterization for cluster lensing tomography that avoids redshift binning and demonstrates its effectiveness in detecting tomography and constraining cluster mass profiles.

Findings

Mass-richness calibration consistent with previous SDSS results

Successful detection of tomography without redshift binning

Low-redshift tomography can constrain cluster mass profiles

Abstract

The shapes of distant galaxies are sheared by intervening galaxy clusters. We examine this effect in Stripe 82, a 275 square degree region observed multiple times in the Sloan Digital Sky Survey and coadded to achieve greater depth. We obtain a mass-richness calibration that is similar to other SDSS analyses, demonstrating that the coaddition process did not adversely affect the lensing signal. We also propose a new parameterization of the effect of tomography on the cluster lensing signal which does not require binning in redshift, and we show that using this parameterization we can detect tomography for stacked clusters at varying redshifts. Finally, due to the sensitivity of the tomographic detection to accurately marginalizing over the effect of the cluster mass, we show that tomography at low redshift (where dependence on exact cosmological models is weak) can be used to constrain mass profiles in clusters.