Dr. Christopher Kochanek of the Ohio State University will continue his variability-monitoring program of approximately 25 gravitational lens systems, using telescopes in both northern and southern hemispheres. Three unique subjects will be studied: (1) The structure of dark matter halos of early-type galaxies, using measurements of time delays in gravitational lenses; (2) The mean stellar mass in lens galaxies, using the microlensing of quasars by the stars in the lens galaxy; and (3) The spatial structure of quasar accretion disks, using the microlensing of gravitationally lensed quasars to measure disk sizes as a function of wavelength. The project will significantly expand the number and accuracy of accretion disk size measurements, thereby providing the data needed to rigorously test models of accretion disk structure.
The project will contribute to teaching and training of students at both the graduate and undergraduate levels. The results will be broadly disseminated through publication in both archival journals and on-line archives. The general results are being used more broadly to educate the public through local lecture programs at the Perkins Observatory (in Ohio), national press releases, and a middle school student/teacher training program being developed with the Center of Science and Industry, the large science museum in Columbus.
