The DECADE cosmic shear project I: A new weak lensing shape catalog of 107 million galaxies

TL;DR

This paper introduces a new weak lensing galaxy shape catalog with 107 million galaxies from DECam data, thoroughly characterized for cosmology use, and demonstrates its potential for competitive cosmological constraints.

Contribution

The paper presents a large, well-characterized weak lensing galaxy shape catalog from DECam data, including systematic bias analysis and a shear calibration pipeline, suitable for cosmological studies.

Findings

Catalog covers 5412 deg² with 4.59 galaxies per arcmin².

Measured shear multiplicative bias is approximately -2.45%.

Catalog quality is sufficient for competitive cosmological constraints.

Abstract

We present the Dark Energy Camera All Data Everywhere (DECADE) weak lensing dataset: a catalog of 107 million galaxies observed by the Dark Energy Camera (DECam) in the northern Galactic cap. This catalog was assembled from public DECam data including survey and standard observing programs. These data were consistently processed with the Dark Energy Survey Data Management pipeline as part of the DECADE campaign and serve as the basis of the DECam Local Volume Exploration survey (DELVE) Early Data Release 3 (EDR3). We apply the Metacalibration measurement algorithm to generate and calibrate galaxy shapes. After cuts, the resulting cosmology-ready galaxy shape catalog covers a region of $5,\!412 \,\,{\rm deg}^2$ with an effective number density of $4.59\,\, {\rm arcmin}^{-2}$. The coadd images used to derive this data have a median limiting magnitude of $r = 23.6$, $i = 23.2$, and $z = 22.6$, estimated at ${\rm S/N} = 10$ in a 2 arcsecond aperture. We present a suite of detailed studies to characterize the catalog, measure any residual systematic biases, and verify that the catalog is suitable for cosmology analyses. In parallel, we build an image simulation pipeline to characterize the remaining multiplicative shear bias in this catalog, which we measure to be $m = (-2.454 \pm 0.124) \times10^{-2}$ for the full sample. Despite the significantly inhomogeneous nature of the data set, due to it being an amalgamation of various observing programs, we find the resulting catalog has sufficient quality to yield competitive cosmological constraints.