Dark Energy Survey Year 1 Results: Weak Lensing Shape Catalogues

TL;DR

This paper presents two galaxy shape catalogues from the Dark Energy Survey Year 1 data, using two independent shear measurement pipelines, demonstrating their suitability for weak lensing analysis.

Contribution

Introduction of two new galaxy shape catalogues with innovative calibration methods from DES Year 1 data, enabling improved weak lensing studies.

Findings

Catalogues contain 34.8 million and 21.9 million objects.

Both catalogues pass null tests confirming data quality.

Estimated shear calibration uncertainties are 0.013 and 0.025.

Abstract

We present two galaxy shape catalogues from the Dark Energy Survey Year 1 data set, covering 1500 square degrees with a median redshift of $0.59$. The catalogues cover two main fields: Stripe 82, and an area overlapping the South Pole Telescope survey region. We describe our data analysis process and in particular our shape measurement using two independent shear measurement pipelines, METACALIBRATION and IM3SHAPE. The METACALIBRATION catalogue uses a Gaussian model with an innovative internal calibration scheme, and was applied to $riz$-bands, yielding 34.8M objects. The IM3SHAPE catalogue uses a maximum-likelihood bulge/disc model calibrated using simulations, and was applied to $r$-band data, yielding 21.9M objects. Both catalogues pass a suite of null tests that demonstrate their fitness for use in weak lensing science. We estimate the 1$\sigma$ uncertainties in multiplicative shear calibration to be $0.013$ and $0.025$ for the METACALIBRATION and IM3SHAPE catalogues, respectively.