The variability of the broad emission lines in the spectra of active galactic nuclei reveals fundamental information about the structure and kinematics of the line-emitting region and about the nature of the central source. The work to be supported by this grant will provide, for the first time, detailed, model-independent mappings of the structure of active galactic nuclei. The goal of this program is to determine the structure and kinematics of the braod-line emitting regions in active nuclei through repeated observations of a limited number of sources. This is information about active galactic nuclei which cannot be obtained in any other way. The Principal Investigator is regarded as one of the leaders in this area of research.
