Details

Autor(en) / Beteiligte

• Hildebrandt, H.
• Köhlinger, F.
• van den Busch, J. L.
• Joachimi, B.
• Heymans, C.
• Kannawadi, A.
• Wright, A. H.
• Asgari, M.
• Blake, C.
• Hoekstra, H.
• Joudaki, S.
• Kuijken, K.
• Miller, L.
• Morrison, C. B.
• Tröster, T.
• Amon, A.
• Archidiacono, M.
• Brieden, S.
• Choi, A.
• de Jong, J. T. A.
• Erben, T.
• Giblin, B.
• Mead, A.
• Peacock, J. A.
• Radovich, M.
• Schneider, P.
• Sifón, C.
• Tewes, M.

Titel

KiDS+VIKING-450: Cosmic shear tomography with optical and infrared data

Ist Teil von

• Astronomy and astrophysics (Berlin), 2020-01, Vol.633, p.A69

Ort / Verlag

Heidelberg: EDP Sciences

Erscheinungsjahr

2020

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• We present a tomographic cosmic shear analysis of the Kilo-Degree Survey (KiDS) combined with the VISTA Kilo-Degree Infrared Galaxy Survey. This is the first time that a full optical to near-infrared data set has been used for a wide-field cosmological weak lensing experiment. This unprecedented data, spanning 450 deg 2 , allows us to significantly improve the estimation of photometric redshifts, such that we are able to include robustly higher-redshift sources for the lensing measurement, and – most importantly – to solidify our knowledge of the redshift distributions of the sources. Based on a flat ΛCDM model we find S 8 ≡ σ 8 Ω m /0.3 = 0.737 +0.040 −0.036 in a blind analysis from cosmic shear alone. The tension between KiDS cosmic shear and the Planck-Legacy CMB measurements remains in this systematically more robust analysis, with S 8 differing by 2.3 σ . This result is insensitive to changes in the priors on nuisance parameters for intrinsic alignment, baryon feedback, and neutrino mass. KiDS shear measurements are calibrated with a new, more realistic set of image simulations and no significant B-modes are detected in the survey, indicating that systematic errors are under control. When calibrating our redshift distributions by assuming the 30-band COSMOS-2015 photometric redshifts are correct (following the Dark Energy Survey and the Hyper Suprime-Cam Survey), we find the tension with Planck is alleviated. The robust determination of source redshift distributions remains one of the most challenging aspects for future cosmic shear surveys.