The Euclid project

Cristobal Padilla

The Euclid group at IFAE is lead by Cristobal Padilla, who is the Project Manger of the NISP-FWA and coordinates the group of engineers and technicians to fulfill the Institute responsibilities in Euclid. Some of the postdocs and students in the Cosmology group also help, specially in the preparation of the data and usage of PAU for Euclid science.

Introduction

Euclid is a mission for the European Space Agency (ESA) Cosmic Vision (CV) 2015-25 programme to explore how the Universe evolved over the past 10 billion years to address questions related to fundamental physics and cosmology on the nature and properties of dark energy, dark matter and gravity, as well as on the physics of the early universe and the initial conditions which seed the formation of cosmic structure.

Euclid Goals

To accomplish its goals, Euclid will carry out a wide survey of 15,000 deg2 of the sky free of contamination by light from the Milky Way and the Solar System and a 40 deg2 deep survey to measure the high-redshift universe. The complete survey represents hundreds of thousands of images and several tens of Petabytes of data. Euclid will observe about 10 billion sources out of which more than one billion will be used for weak lensing. Several tens of million galaxy redshifts will be also measured and used for galaxy clustering. With these images Euclid will probe the expansion history of the Universe and the evolution of cosmic structures by measuring the modification of shapes of galaxies induced by gravitational lensing effects of dark matter and the 3-dimension distribution of structures from spectroscopic redshifts of galaxies and clusters of galaxies. Euclid data will provide improvement factors of ~30 in the measurement of the neutrino mass and up to ~400 in the uncertainty of the parameters of the cosmology state equation and will leave legacy catalogs in may areas of galaxy science with exquisite imaging quality and superb Near Infrared Spectroscopy.

Figure 1: Artist View of the Euclid satellite (Copyright ESA).

Euclid Instruments

The Satellite will be equipped with a 1.2 m diameter Silicon Carbide (SIC) mirror telescope made by Airbus Defense and Space feeding 2 instruments, VIS and NISP, built by the Euclid Consortium. These instruments are a high quality panoramic visible imager (VIS), a near infrared 3-filter photometer (NISP-P) and a slitless spectrograph (NISP-S). The IFAE is responsible for the design and manufacturing of the NISP Filter Wheel Assembly (NISP-FWA), a device that allows the NISP instrument to select the optical filter used for the images it takes.

IFAE contribution in 2019

The group has started activities inside the Euclid consortium to exploit the data and contribute to the scientific output of the mission

During 2019, IFAE has been supporting LAM in the integration and testing of the FWA inside the NISP system. Tests have been progressing well and it is expected that the NISP instrument is delivered for integration inside the Euclid satellite during 2020.

On the other front, the group has started activities inside the Euclid consortium to exploit the data and contribute to the scientific output of the mission. The activities have been more focused in the analysis of the PAU data with Machine Learning techniques, where we have made studies on star-galaxy separation, background prediction and Photometric redshift measurements with deep learning techniques. We have also joined the new Machine Learning Working group in Euclid to start exporting these techniques to this survey.

ASTEROID

ASTEROID is an H2020 project aiming at enabling Europe to acquire the technology and knowledge necessary to manufacture 2k^2 high performance Infrared Focal Plane Arrays, define the types of products to design and define the strategy to create an industrial manufacturing line of these detectors. IFAE is partnering with companies and institutions in France and Austria to develop a low noise and low dark current detector that will be directly useful for astronomy application in both ground telescopes (ESO) or space telescopes (ESA).

IFAE’s responsibility is in the optical and electrical characterisation of the detector. During 2019, we have commissioned the equipment used and modified for Euclid GSE to perform the thermal cycles needed in the controlled and secured way. At the same we have also integrated all the optical elements needed for the detector characterisation. The European Southern Observatory (ESO) New Generation Controller (NGC) for the test of the Infrared Sensors is expected delivery during 2020, as well as the detectors from Lynred.

This project will allow IFAE to acquire the know-how in characterizing IR sensors for Astronomy and Space and establishes a possible link of future collaboration with other ESO missions and their world-class telescopes located in the Atacama Desert in Chile. More information can be found in asteroidh2020.eu , maintained by IFAE as communication responsible of the project.