Dark Energy Survey Year 1 Results: Curved-Sky Weak Lensing Mass Map

Abstract

We construct the largest curved-sky galaxy weak lensing mass map to date from the DES first-year (DES Y1) data. The map, about 10 times larger than previous work, is constructed over a contiguous $\approx 1,500$deg${}^2$, covering a comoving volume of $\approx 10$Gpc${}^3$. The effects of masking, sampling, and noise are tested using simulations. We generate weak lensing maps from two DES Y1 shear catalogs, Metacalibration and Im3shape, with sources at redshift $0.2<z<1.3,$ and in each of four bins in this range. In the highest signal-to-noise map, the ratio between the mean signal-to-noise in the E-mode and the B-mode map is $\sim$1.5 ($\sim$2) when smoothed with a Gaussian filter of $\ddot{I}{ƒ}_G=30$ (80) arcminutes. The second and third moments of the convergence $\hat{I}º$ in the maps are in agreement with simulations. We also find no significant correlation of $\hat{I}º$ with maps of potential systematic contaminants. Finally, we demonstrate two applications of the mass maps: (1) cross-correlation with different foreground tracers of mass and (2) exploration of the largest peaks and voids in the maps.

25 pages, 19 figures, 1 table; revision with changes implemented according to journal referee