This project will take advantage of the gravitational bending of light to observe a very distant galaxy whose image is being magnified by the gravity of a cluster of galaxies in the foreground. By carefully studying the magnification of the distant galaxy they will learn about the mass distribution in the foreground cluster. This galaxy is unique because one star in that galaxy has been magnified enough to be seen at a distance of billions of lightyears. By observing changes in brightness of this star, they will learn about the masses of stars in the foreground cluster of galaxies. The project will also develop several exhibits for he Bell Museum at the University of Minnesota-Twin Cities.
The project will compare different lens mass models with the surface brightness spatial variations across the lensed galaxy images to determine the most accurate mass distribution map of the lensing cluster. By obtaining a 3-year light curve for the single, highly magnified star, using the Large Binocular Telescope, they will be able to measure microlensing light fluctuations that can be used to constrain the mass function of the intracluster stars in the foreground cluster. This will help place constraints on the initial mass function.
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.
