9422075 Hough Radio and optical studies of quasars will be carried out in order to contribute toward the unification of the physical models which describe the active galaxies and quasars. Quasars are thought to be young, distant, powerful galaxies that may harbor supermassive black holes in their central regions. However, they may be just an extreme example of the general phenomenon of active galaxies in which unusually large power output from the nuclear regions is observed. In order to test the various hypotheses that attempt to unite the theories about the quasars with other active galaxies - including BL Lac objects, radio galaxies, and Seyfert galaxies - a carefully selected, complete sample of twenty-five of the most powerful quasars known will be studied. Radio telescopes working in unison as interferometers will be used to Make radio wavelength images of the quasars, from their very centers to huge radio-emitting regions up to a million light-years away. The time sequences of images for the central regions will permit a study of apparent faster-than-light, or "superluminal", motion observed in these quasars. Optical observations will be made to obtain the spectra of the light emitted from these quasars, and hence we will learn something of the physical state of the gas surrounding the central object. The statistics of various radio and optical properties of these quasars will be used for rigorous tests of "unified models". The results of the observations may possibly be used to calculate the size and age of the universe. Additional observations, which will push the resolution limits of the radio astronomy techniques, will be carried out.
