Narrow Results

In recent years researchers have begun to realize that the classification system used for active galaxies requires some changes. “Unification” refers to the merging of two or more AGN subclasses into a single subclass, usually by understanding that inclination effects or some other relatively uninteresting parameter controls how the object is classified. Once these superficial effects are understood we can get past them to the real physics of the AGN. This chapter describes the current state of unification of several common subclasses of AGN, with a view to showing what researchers can look for and avoid in classifying and understanding these objects.