Wide-Field Lensing Mass Maps from DES Science Verification Data

TL;DR

This paper presents a wide-field mass map from DES data using weak lensing, revealing dark matter structures, confirming known clusters, and detecting correlations with galaxies, supporting cosmological models.

Contribution

It introduces a new large-scale mass mapping technique from DES data, validating its accuracy and consistency with LCDM simulations.

Findings

Mass map agrees with galaxy clusters and identifies super-clusters and voids.

Strong correlation between mass map and galaxy distribution at 5-7 sigma.

Results are consistent with LCDM N-body simulations, indicating low systematics.

Abstract

We present a mass map reconstructed from weak gravitational lensing shear measurements over 139 sq. deg from the Dark Energy Survey (DES) Science Verification data. The mass map probes both luminous and dark matter, thus providing a tool for studying cosmology. We find good agreement between the mass map and the distribution of massive galaxy clusters identified using a red-sequence cluster finder. Potential candidates for super-clusters and voids are identified using these maps. We measure the cross-correlation between the mass map and a magnitude-limited foreground galaxy sample and find a detection at the 5-7 sigma level on a large range of scales. These measurements are consistent with simulated galaxy catalogs based on LCDM N-body simulations, suggesting low systematics uncertainties in the map. We summarize our key findings in this letter; the detailed methodology and tests for systematics are presented in a companion paper.