Euclid Quick Data Release (Q1). Photometric redshifts and physical properties of galaxies through the PHZ processing function

Understand

The ESA Euclid mission will measure the photometric redshifts of billions of galaxies in order to provide an accurate 3D view of the Universe at optical and near-infrared wavelengths.

• Photometric redshifts are determined by the PHZ processing function on the basis of the multi-wavelength photometry of Euclid and ground-based observations.
• In this paper, we describe the PHZ processing used for the Euclid Quick Data Release, the output products, and their validation.
• The PHZ pipeline is responsible for the following main tasks: source classification into star, galaxy, and QSO classes based on photometric colours; determination of photometric redshifts and of physical properties of galaxies.