Poster Abstract

P10.34 Willeke Mulder (Kapteyn Astronomical Institute, University of Groningen)

Theme: Data processing pipelines

Precision calibration software system for Euclid's ground-based imaging data

ESA’s upcoming Euclid mission will construct a 3D map of the distribution of a billion galaxies to constrain the expansion history of the universe. Ground-based imaging data is essential to obtain their distances through photometric redshifts. This poses extremely challenging requirements in terms of accuracy of both colors and positions. The Euclid Survey covers 15,000 square degrees spread over the Northern and Southern hemisphere. Thus imaging data from several different observatories needs to be combined into a homogeneous data set that is on the Euclid photometric and astrometric reference system.
The Euclid External Data team inside the Euclid Science Ground Segment develops the software system validating the ground-based data and performing recalibration / refinement of photometry and astrometry. A major challenge is achieving the required levels of astrometric accuracy for a heterogeneous set of imaging surveys efficiently and accurately, as the astrometric reference frame for EXT will evolve based on new Gaia and Euclid VIS releases. A database table handling system will implement this changing reference frame as well as validation and calibration procedures.
In this contribution we present the overall architecture of the Euclid External Data software system, with a focus on the astrometric validation and calibration and the database table handling system.