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

TL;DR

This paper develops a detailed simulated catalog of strongly lensed gravitational wave events using a comprehensive halo model, predicting detection rates and characteristics for future ground-based detectors, aiding in identification and analysis.

Contribution

It introduces a new, physically grounded mock catalog of lensed GW events incorporating complex lens models and diverse source populations, enhancing prediction accuracy for future detections.

Findings

Forecasts ~400 doublets and 36 quadruplets annually with ET+CE.

Includes subhalo-lensed and complete multi-image systems in simulations.

Predicts ~360 high-magnification events and ~617 events under relaxed detection criteria.

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 catalog 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 the earth 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 ET+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 ($\mu > 3$), 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 event rates, as well as the distributions of SNR pairs and time delays. These results establish a more physically grounded statistical prior for the future identification and authentication of lensed GW signals. The Gravitational Waves-Lensing Mock Catalog (GW-LMC) have been made publicly available.