Speaker
Description
Galaxy–galaxy strong lensing (GGSL) in galaxy clusters provides a unique probe of the mass distributions of individual cluster member galaxies. However, its definition and identification can depend sensitively on the assumed properties of these galaxies. We systematically investigate how the commonly adopted GGSL criterion responds to variations in the truncation radius and velocity dispersion of cluster member galaxies, and use these results to inform a physically motivated definition of GGSL with enhanced stability. We further explore the implications of this treatment for strong lensing modelling of the galaxy cluster MACS J1206.2−0847. In particular, we introduce a physically motivated hierarchical approach that relaxes the conventional assumption of scatter-free scaling relations for cluster member galaxies, allowing for intrinsic variations in their properties. As survey depth and angular resolution continue to improve, this approach may provide deeper insights into the properties of individual cluster member galaxies, and offering a new perspective on their population-level variations.