Chapter 4: Scaling Up Lensing

In chapter 4, we scale lens modeling up beyond a single lens galaxy: extra galaxies, multi-galaxy lenses, scaling relations, group and cluster scales, and weak lensing.

The chapter contains the following tutorials:

Tutorial 1: Extra Galaxies - Handling nearby galaxies by scaling their light out of the fit or modeling them explicitly.

Tutorial 2: Multi Galaxy - Modeling lenses with two or more co-dominant lens galaxies and the degeneracies this creates.

Tutorial 3: Scaling Relation - Tying galaxy masses to their luminosities so model complexity stops growing with each galaxy.

Tutorial 4: Group Scale - Modeling group-scale lenses with truncated dPIE members and an optional group dark matter halo.

Tutorial 5: Cluster Scale - Modeling cluster-scale lenses with point-source positions, the CSV interface and multi-plane ray tracing.

Tutorial 6: Weak Lensing - Fitting weak-lensing shear catalogues, which probe mass far beyond the strong lensing region.