KiDS-i-800: Comparing weak gravitational lensing measurements from same-sky surveys

Journal article

We present a weak gravitational lensing analysis of 815 deg2of i-band imaging from the Kilo-Degree Survey (KiDS-i-800). In contrast to the deep r-band observations, which take priority during excellent seeing conditions and form the primary KiDS data set (KiDS-r-450), the complementary yet shallower KiDS-i-800 spans a wide range of observing conditions. The overlapping KiDS-i-800 and KiDS-r-450 imaging therefore provides a unique opportunity to assess the robustness of weak lensing measurements. In our analysis we introduce two new 'null' tests. The 'nulled' two-point shear correlation function uses a matched catalogue to show that the calibrated KiDS-i-800 and KiDS-r-450 shear measurements agree at the level of 1 ± 4 per cent.We use five galaxy lens samples to determine a 'nulled' galaxy-galaxy lensing signal from the full KiDS-i-800 and KiDS-r-450 surveys and find that the measurements agree to 7 ± 5 per cent when the KiDS-i-800 source redshift distribution is calibrated using either spectroscopic redshifts, or the 30-band photometric redshifts from the COSMOS survey.

Authors: Amon, A; Heymans, C; Klaes, D; Erben, T; Blake, C

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Oxford University Press
• Journal: Monthly Notices of the Royal Astronomical Society
• Volume: 477
• Issue: 4
• Pages: 4285-4307
• Publication date: 2018-04-05
• Acceptance date: 2018-04-03
• DOI: 10.1093/mnras/sty859
• EISSN: 1365-2966
• ISSN: 0035-8711
• Keywords: surveys; cosmology: observations; gravitational lensing: weak; galaxies: photometry