Dark Energy Survey Year 1 Results: Weak Lensing Shape Catalogues

• Published in: Monthly Notices of the Royal Astronomical Society
• Main Authors: Zuntz, J., Eifler, T. F., DES Collaboration
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Royal Astronomical Society 2018
• Subjects: gravitational lensing: weak –methods: data analysis – techniques: image processing – catalogues – surveys – cosmology: observations; South Pole; Stripe; McClintock; South pole
• Online Access: https://doi.org/10.1093/mnras/sty2219

We present two galaxy shape catalogues from the Dark Energy Survey Year 1 data set, covering 1500 deg^2 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 1σ uncertainties in multiplicative shear calibration to be 0.013 and 0.025 for the METACALIBRATION and IM3SHAPE catalogues, respectively. © 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model). Accepted 2018 August 7. Received 2018 July 17; in original form 2017 August 3; Published: 18 August 2018. We thank Rachel Mandelbaum and the GREAT3 team for providing the COSMOS galaxy images used for the im3shape calibration. We are also grateful to the eyeballing volunteers, among them Mandeep Gill, Annalisa Mana, Ben Mawdsley, Tom McClintock, Alessandro Nastasi, and Corvin Stern, for their help with validating the COSMOS galaxy images. Support for DG was provided by NASA through the Einstein Fellowship Program, grant PF5-160138 awarded by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for NASA under contract NAS8-03060. ES was supported by DOE grant DE-AC02-98CH10886. MJ, BJ, and ...