Published online by Cambridge University Press: 30 March 2016
The principal motivation behind the work summarized below was to define the nature of a “typical” galactic nucleus and thereby determine whether such nuclei differ from active nuclei in a qualitative or only quantitative sense. I hoped that such a study would then yield clues as to the origin and duration of nuclear activity and the effects such activity might have on the structure and evolution of the surrounding galaxy. For a more complete discussion of the results below, see my Ph. D. dissertation (Heckman, 1978) or the series of three papers (Heckman, 1979) to be published elsewhere.