Euclid preparation VIII. The complete calibration of the colour-redshift relation survey: VLT/KMOS observations and data release
The Complete Calibration of the Colour-Redshift Relation survey (C3R2) is a spectroscopic e ffort involving ESO and Keck facilities designed specifically to empirically calibrate the galaxy colour-redshift relation - P(z jC) to the Euclid depth (iAB = 24 :5) and is intimately linked to the success of upcoming Stage IV dark energy missions based on weak lensing cosmology. The aim is to build a spectroscopic calibration sample that is as representative as possible of the galaxies of the Euclid weak lensing sample. In order to minimise the number of spectroscopic observations necessary to fill the gaps in current knowledge of the P(z jC), self-organising map (SOM) representations of the galaxy colour space have been constructed. Here we present the first results of an ESO@VLT Large Programme approved in the context of C3R2, which makes use of the two VLT optical and near-infrared multi-object spectrographs, FORS2 and KMOS. This data release paper focuses on high-quality spectroscopic redshifts of high-redshift galaxies observed with the KMOS spectrograph in the near-infrared H- and K-bands. A total of 424 highly-reliable redshifts are measured in the 1:3 2 galaxies. ; European Space Agency European Commission Academy of Finland European Commission Agenzia Spaziale Italiana (ASI) Belgian Federal Science Policy Office Canadian Euclid Consortium Centre National D'etudes Spatiales Helmholtz Association German Aerospace Centre (DLR) Danish Space Research Institute Fundacao para a Cienca e a Tecnologia Spanish Government National Aeronautics & Space Administration (NASA) Netherlandse Onderzoekschool Voor Astronomie Norvegian Space Center Romanian Space Agency State Secretariat for Education, Research and Innovation (SERI) at the Swiss Space Office (SSO) United Kingdom Space Agency ESO programme 199.A-0732 Helmholtz Association German Aerospace Centre (DLR) 50 QE 1101 Spanish Ministry of Science, Innovation and Universities ESP2017-89838-C3-1-R H2020 programme of the European Commission 776247 Swiss National Science Foundation (SNSF) European Commission PRIN MIUR 2015 "Cosmology and Fundamental Physics: Illuminating the Dark Universe with Euclid"