Strong gravitational lenses captured by Euclid

This image shows examples of gravitational lenses that Euclid captured in its first observations of the Deep Field areas. Using an initial sweep by artificial intelligence models, followed by citizen science inspection, expert vetting and modelling, a first catalogue of 500 galaxy-galaxy strong lens candidates was created, almost all of which were previously unknown. This type of lensing happens when a foreground galaxy and its halo of dark matter acts as a lens, distorting the image of a background galaxy along the line of sight towards Euclid. With the help of these models, Euclid will capture some 7000 candidates in the major cosmology data release planned for the end of 2026, and in the order of 100 000 galaxy-galaxy strong lenses by the end of the mission, around 100 times more than currently known. [Image description: A collage of fourteen by eight squares containing examples of gravitational lenses. Each example typically comprises a bright centre with smears of stars in an arc or multiple arcs around it as a result of light travelling towards Euclid from distant galaxies being bent and distorted by normal and dark matter in the foreground. In some rare cases the smearing is in a complete ring, creating a so-called Einstein Ring.]