Mock Catalogs of Strongly Lensed Gravitational Waves via a Halo Model Approach with Ground-based Detectors

Abstract As plans for the construction of third-generation gravitational-wave (GW) detectors advance, research into strongly lensed GWs has become increasingly critical. It is anticipated that hundreds of multi-image lensed GWs will be detected annually. We present a comprehensive suite of lensed GW mock catalogs derived from a composite lens mass model incorporating dark matter halos, galaxies, and subhalos. We analyze three source populations with four detector network configurations considering Earth’s rotation. Our simulations encompass not only conventional doublets and quadruplets but also subhalo-lensed events, highly magnified systems, and complete three- or five-image systems with a detectable central image, a feature distinct from optical lensing. For the joint Einstein Telescope (ET) + Cosmic Explorer (CE) network, we forecast an annual detection rate of approximately 400 doublets and 36 quadruplets. Notably, this population includes roughly 107 events lensed by subhalos and 20 complete systems with detectable central images. Furthermore, we analyze high-magnification events ( μ > 3), predicting approximately 360 such cases. Under a more relaxed selection criterion that requires only at least one lensed signal to exceed the detection threshold, we estimate a total of approximately 617 lensed events. We also investigate the impact of variations in lens mass models and stellar evolution models on the event rates, as well as the distribution of signal-to-noise ratio and time-delay pairs. These results establish a more physically grounded statistical prior for the future identification and authentication of lensed GW signals. The GW lensing mock catalog has been made publicly available.