Galaxy clusters act as "cosmic telescopes" that magnify distant galaxies, making them appear bigger and brighter and therefore easier to detect. If we want to better understand the intrinsic properties of the distant galaxies, it is important to make a "lens model" of the mass distribution of the cluster to make a model of the magnifications of the distant galaxies. All current models seem to missing something since they disagree with each other. This project will look at the assumptions and missing effects from the current models to try to build a better understanding of the uncertainties in lens models.
The proposed project will improve the state of gravitational lens modeling by developing a framework for reconciling discrepancies between different models for reconstructing lensing maps. The project will incorporate four new effects: scatter in cluster member galaxy properties, lensing by line-of-sight galaxies outside the cluster, structure along the line of sight, and non-galaxy structure within the cluster. They will use this framework to see whether the new effects can reconcile current lens models, and present the framework as an open-source code module so that it can be used in future cluster lens modeling.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
