2022AJ....163..139Y

We present a mock catalog of gravitationally-lensed quasars at z_qso < 7.5 with simulated images for the Rubin Observatory Legacy Survey of Space and Time (LSST). We adopt recent measurements of quasar-luminosity functions to model the quasar population, and use the CosmoDC2 mock galaxy catalog to model the deflector galaxies, which successfully reproduces the observed galaxy-velocity dispersion functions up to z_d ∼ 1.5. The mock catalog is highly complete for lensed quasars with Einstein radius θ_E > 0.''07 and quasar absolute magnitude M_i < - 20. We estimate that there are ∼10³ lensed quasars discoverable in current imaging surveys, and LSST will increase this number to ∼ 2.4 x 10³. Most of the lensed quasars have image separation Δθ > 0.''5, which will at least be marginally resolved in LSST images with seeing of ∼0.''7. There will be ∼200 quadruply-lensed quasars discoverable in the LSST. The fraction of quad lenses among all discoverable lensed quasars is about ∼10%-15%, and this fraction decreases with survey depth. This mock catalog shows a large diversity in the observational features of lensed quasars, in terms of lensing separation and quasar-to-deflector flux ratio. We discuss possible strategies for a complete search of lensed quasars in the LSST era.