Euclid Quick Data Release (Q1). XLIII. The Strong Lensing Discovery Engine F -- Bright and low-redshift strong lenses
Abstract
We present 72 additional galaxy-galaxy strong lenses that complement the sample discovered in the Euclid Quick Release 1 data (63.1, catalogue, caused us to miss several bright and low-redshift strong lenses. They add more than 10% of new strong-lens candidates compared to the previous search. In total, the catalogue includes 38 grade A (confident) and 34 grade B (probable) candidates. These lenses were identified through a combination of two independent searches for bright nearby objects: one search was based on machine-learning models followed by expert visual inspection, and the other search was based solely on expert visual inspection, targeting objects that were not included in the initial machine-learning selection (a limitation identified only after extensive visual inspection). With these additional strong-lens candidates, we augment the expected number of high-confidence candidates in the Euclid Wide Survey from previous forecasts to . Detailed semi-automated lens modelling confirmed at least 41 systems out of 72. This fraction is consistent with that found in SLDE A (315 out of 488). They include multiple edge-on disc lenses, sources with arcs near the lens centre, red sources, and an edge-on disc galaxy that lenses a galaxy merger, which produces two sets of lensed features, an Einstein ring and a doubly imaged component. The median redshift of these systems is lower by Δ z ∼ 0.3 than that of the SLDE A sample. of the strong-lens discovery engine (SLDE) papers A–E. We show that the previous pre-selection of potential lenses, which excluded objects from the Gaia 120000