The effects of varying depth in cosmic shear surveys

• Published in: Astronomy and astrophysics (Berlin) Vol. 634; p. A104
• Main Authors: Heydenreich, Sven, Schneider, Peter, Hildebrandt, Hendrik, Asgari, Marika, Heymans, Catherine, Joachimi, Benjamin, Kuijken, Konrad, Lin, Chieh-An, Tröster, Tilman, van den Busch, Jan Luca
• Format: Journal Article
• Language: English
• Published: Heidelberg EDP Sciences 01.02.2020
• Subjects: Shear
• ISSN: 0004-6361; 1432-0746
• DOI: 10.1051/0004-6361/201936966

We present a semi-analytic model for the shear two-point correlation function of a cosmic shear survey with non-uniform depth. Ground-based surveys are subject to depth variations that primarily arise through varying atmospheric conditions. For a survey like the Kilo-Degree Survey (KiDS), we find that the measured depth variation increases the amplitude of the observed shear correlation function at the level of a few percent out to degree-scales, relative to the assumed uniform-depth case. The impact on the inferred cosmological parameters is shown to be insignificant for a KiDS-like survey. For next-generation cosmic shear experiments, however, we conclude that variable depth should be accounted for.