Answers are grounded in this paper and cite their sources.
Aims. We attempt to place very accurate positional constraints on seven gravitationally lensed quasars currently being monitored by the COSMOGRAIL collaboration, and shape parameters for the light distribution of the lensing galaxy. We attempt to determine simple mass models that reproduce the observed configuration and predict time delays. We finally test, for the quads, whether there is evidence of astrometric perturbations produced by substructures in the lensing galaxy, which may preclude a good fit with the simple models.
No takes yet. Share an insight, caveat, or question.
Chantry et al. (2010) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: