Euclid Quick Data Release (Q1): The Strong Lensing Discovery Engine A -- System overview and lens catalogue

Abstract

We present a catalogue of 497 galaxy-galaxy strong lenses in the Euclid Quick Release 1 data (63 deg${}^2$). In the initial 0.45\% of Euclid's surveys, we double the total number of known lens candidates with space-based imaging. Our catalogue includes 250 grade A candidates, the vast majority of which (243) were previously unpublished. Euclid's resolution reveals rare lens configurations of scientific value including double-source-plane lenses, edge-on lenses, complete Einstein rings, and quadruply-imaged lenses. We resolve lenses with small Einstein radii (${\theta }_{\mathrm{E}}<1^{\prime \prime }$) in large numbers for the first time. These lenses are found through an initial sweep by deep learning models, followed by Space Warps citizen scientist inspection, expert vetting, and system-by-system modelling. Our search approach scales straightforwardly to Euclid Data Release 1 and, without changes, would yield approximately 7000 high-confidence (grade A or B) lens candidates by late 2026. Further extrapolating to the complete Euclid Wide Survey implies a likely yield of over 100000 high-confidence candidates, transforming strong lensing science.

Data: https://doi.org/10.5281/zenodo.15003116. Paper submitted as part of the A&A Special Issue `Euclid Quick Data Release (Q1)'. 20 pages, 11 figures, plus appendices

Cited by in corpus (7)

• Unveiling a 36 Billion Solar Mass Black Hole at the Centre of the Cosmic Horseshoe Gravitational Lens
• The COSMOS-Web Lens Survey (COWLS) II: depth, resolution, and NIR coverage from JWST reveal 17 spectacular lenses
• The COSMOS-Web Lens Survey (COWLS) III: forecasts versus data
• JWSTs PEARLS: NIRCam imaging and NIRISS spectroscopy of a $z=3.6$ star-forming galaxy lensed into a near-Einstein Ring by a $z=1.258$ massive elliptical galaxy
• Using Strong Lensing to Detect Subhalos with Steep Inner Density Profiles
• Detecting the hidden population of low-mass haloes in strong lenses
• Lensed stars in galaxy-galaxy strong lensing -- a JWST prediction for the Cosmic Horseshoe