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KiDS+VIKING-450 and DES-Y1 combined: Cosmology with cosmic shear

Research output: Contribution to journalLetter

  • S. Joudaki
  • H. Hildebrandt
  • D. Traykova
  • N. E. Chisari
  • C. Heymans
  • A. Kannawadi
  • K. Kuijken
  • A. H. Wright
  • M. Asgari
  • T. Erben
  • H. Hoekstra
  • B. Joachimi
  • L. Miller
  • T. Tröster
  • J. L. van den Busch

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Original languageEnglish
Article numberL1
Number of pages8
JournalAstronomy and Astrophysics
Early online date29 May 2020
Publication statusPublished - 1 Jun 2020


We present a combined tomographic weak gravitational lensing analysis of the Kilo Degree Survey (KV450) and the Dark Energy Survey (DES-Y1). We homogenize the analysis of these two public cosmic shear datasets by adopting consistent priors and modeling of nonlinear scales, and determine new redshift distributions for DES-Y1 based on deep public spectroscopic surveys. Adopting these revised redshifts results in a 0:8δ reduction in the DES-inferred value for S8, which decreases to a 0:5δ reduction when including asystematic redshift calibration error model from mock DES data based on the MICE2 simulation. The combined KV450 + DES-Y1 constraint on S 8 = 0:762+0:025-0:024 is in tension with the Planck 2018 constraint from the cosmic microwave background at the level of 2:5δ. This result highlights the importance of developing methods to provide accurate redshift calibration for current and future weak lensing surveys.

    Research areas

  • astro-ph.CO

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