Collaborative Research: Measuring the physical properties of darkmatter with strong gravitational lensing

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

A gravitational lens is created by a massive object, such as a galaxy or cluster of galaxies, that lies between a distant astronomical source and an observer. The object might not be directly detectable, but it will bend the light from the distant source as the light travels toward the observer. This project will provide a new measurement of the properties of dark matter in quadruple the current number of strong gravitational lenses, significantly enhancing our understanding of the nature of dark matter. In addition, the program will improve the robustness of the dark matter measurement method in preparation for the thousands of gravitational lenses expected to be discovered in the Legacy Survey of Space and Time (LSST). The results will provide new modeling techniques that will reduce the uncertainty associated with the existing dark matter models, and provide a framework to test parameters for a variety of theoretically motivated dark matter models. This project also involves the Cal-Bridge program, which prepares undergraduates from historically under-represented groups for admission to graduate school in physics and astronomy. The investigators will also support the Bobcat Summer STEM academy, a weeklong course which teaches the basics of dark matter and gravitational lensing to K-12 students in the Merced region, an extremely under-served population with only 14% college attainment. This project also involves public talks and the production of new YouTube material for the online “Physics of Sustainable Energy” course. This project will achieve the following objectives: (1) Significantly increase the sample of known gravitational lenses, improving constraints on the half-mode mass of the halo mass function by a factor of 10 in the case of a Cold Dark Matter (CDM) model; (2) Use the multiply-imaged host galaxy of the lensed active galactic nucleus to constrain the deflector macromodel, which will improve our constraints on a turnover in the halo mass function by 0.5 dex; (3) Test a variety of theoretically motivated dark matter models, including several flavors of warm and self-interacting dark matter, and primordial black holes. 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.