The Last Stand Before Rubin: a consolidated sample of strong lensing systems in wide-field surveys (2509.09798v1)

Abstract: As the Vera Rubin Observatory begins its ten-year survey in 2025, it will probe key observables such as strong lensing (SL) by galaxies and clusters. In preparation for this new era, we assemble an extensive compilation of SL candidate systems from the literature, comprising over 30,000 unique objects that can be used as a watch list of known systems. By cross-matching this sample with photometric and spectroscopic catalogs, we construct two value-added tables containing key parameters for SL analysis, including lens and source redshifts and lens velocity dispersions $\sigma_v$. As a preparation for Rubin, we generate image cutouts for these systems in existing wide-field surveys with subarcsecond seeing, namely CFHTLens, CS82, RCSLens, KiDS, HSC, DES, and DESI Legacy. This sample, dubbed the "Last Stand Before Rubin" (LaStBeRu), has a myriad of applications, from using archival data to selections for follow-up projects and training of machine learning algorithms. As an application, we perform a test of General Relativity using these data, combining the effects of motion of massless particles (through SL modeling) and non-relativistic bodies through $\sigma_v$, which allow one to set constraints on the Post-Newtonian parameter $\gamma_\mathrm{PPN}$. Using the LaStBeRu database, we present an independent test of $\gamma_\mathrm{PPN}$ (distinct from previous analyses) and, for the first time, we present such a test exclusively with systems identifiable in ground-based images. By combining these data with the previously published samples, we obtain the most stringent constraint on $\gamma_\mathrm{PPN}$. Our results are consistent with GR at the $\sim$~1-$\sigma$ level and with the previous results from the literature.