The Kilo-Degree Survey

The VLT Survey Telescope at sunset at Paranal Observatory

KiDS, the Kilo-Degree Survey, is a large optical imaging survey in the Southern sky, designed to tackle some of the most fundamental questions of cosmology and galaxy formation of today. Using the VLT Survey Telescope (VST), located at the ESO Paranal Observatory, KiDS will map 1500 square degrees of the night sky in four broad-band filters (u, g, r, i).

Survey overview
Scientific goals



Postal address:

KiDS survey
attn: J. T. A. de Jong
Sterrewacht Leiden
P.O. Box 9513
NL-2300 RA Leiden
The Netherlands

First KiDS+VIKING cosmic shear analysis

16 Dec 2018

The first cosmological measurement based on a combination of KiDS (optical) and VIKING (infrared) data has been presented in Hildebrandt et al. (2018). The area (450 sq.deg.), depth, and wavelength coverage of this first KiDS+VIKING data set make it the most extensive optical+infrared data set ever used for lensing measurements. Based on greatly enhanced photometric redshifts and new image simulations (Kannawadi et al. 2018) this analysis updates the KiDS-450 cosmology results from Hildebrandt et al. (2017) and significantly increases the systematic robustness.

KiDS+VIKING-450 paper and data access

The KiDS-450 weak lensing power spectrum

12 Jun 2017

We use 450 sq. deg. of KiDS imaging data to measure the weak gravitational lensing shear power spectrum with a quadratic estimator in two and three redshift bins. The cosmological parameter that is best constrained by the cosmic shear power spectrum data is a combination of the total matter density Ωm and the clustering amplitude σ8 called S88*√(Ωm/0.3). The constraints derived for this analysis confirm the recently reported tension in this parameter combination with constraints from the Planck cosmic microwave background probe at 3.2σ (we compare also to other data sets in the Figure).

Paper on arXiv
Data products from this analysis


The 1σ constraints on the parameter combination S8 for our fiducial model using 2 and 3 redshift bins. We compare them to constraints from other cosmic shear and CMB analyses. For cosmic shear analyses we indicate the type of estimator used with 'CF' for correlation functions and 'QE' for the quadratic estimator.

Finding galaxy clusters in KiDS

7 Feb 2017

The first galaxy cluster catalog from KiDS, based on the DR2 data set, has been published in Radovich et al. (2017, A&A, 598, A107). Accompanying the paper is a catalog of 1585 candidate clusters, extending to a redshift of 0.7, and shown to be 85% complete, with an estimated purity of 80%. This catalog can be downloaded from the cluster catalog webpage linked below. The tools (developed by F. Bellagamba, M. Maturi and M. Roncarelli) that have been used to harvest the KiDS data for galaxy clusters and presented in this paper, have also been selected for use by the upcoming ESA Euclid satellite mission.

Paper on A&A website
DR2 cluster catalog webpage


Central 2 arcsecond region of the cluster Abell 1411, one of the rich clusters present in the KiDS DR2 area. This color image was made from KiDS u-, g- and r-band data and shows the Brightest Cluster Galaxy, indicated by the green circle; the red circle shows the cluster center reported in the Abell catalog.

KiDS goes to the Galaxy Zoo

1 Feb 2017

Images from the Kilo-Degree Survey (KiDS) are now included in the Galaxy Zoo citizen science project, where anyone can help classify galaxies and contribute to our astronomical knowledge. Currently, for over 11,000 galaxies, selected based on a galaxy catalog from the GAMA survey, color images from KiDS g-, r- and i-band data are available. This data set will later on be extended step-wise to over 40,000 galaxies. The high quality KiDS images will allow us to study the very faintest structures within galaxies, as well as more accurately classify features which may have been missed before.

Galaxy Zoo
Blog post: New images for Galaxy Zoo from GAMA-KiDS!

KiDS-450 Weak lensing shear catalog released

3 Jan 2017

The weak lensing shear catalog for the KiDS-450 / DR3 data set, covering 454 KiDS survey tiles is now publicly available. This data set serves as the basis for the cosmic shear analysis presented in Hildebrandt & Viola et al. (2017) and various more scientific analyses currently in preparation. Available both via ESO and CADC, the catalog provides accurate shear measurements and photometric redshifts for over 15 million galaxies.

KiDS-450 Weak Lensing catalog

Dark matter may be smoother than expected

7 Dec 2016

Analysis of 450 square degrees of the Kilo-Degree Survey (KiDS), made with ESO's VLT Survey Telescope in Chile, suggests that dark matter may be less dense and more smoothly distributed throughout space than previously thought. An international team studied how the light from about 15 million distant galaxies was affected by the gravitational influence of matter on the largest scales in the Universe. The results appear to be in disagreement with earlier results from the Planck satellite. Press releases highlighting these results can be found via the Press releases page.


Dark matter map of KiDS survey region (region G15). Credit: Kilo-Degree Survey Collaboration/H. Hildebrandt & B. Giblin/ESO.