Published online by Cambridge University Press: 14 August 2015
The non-stellar activity in the nuclei of nearby galaxies poses problems of its own. But it gains added interest insofar as it may provide clues to the nature of quasars and the unusually energetic nuclei of some more remote galaxies. The evident qualitative resemblance between these spectacular phenomena and some of the nearby galactic nuclei discussed at this symposium suggests that we may be witnessing a scaled-down or slow-motion version of the same physical mechanism; and the likelihood that dead quasars vastly outnumber living ones suggests that defunct remnants - perhaps displaying some low-level residual activity - may lurk in the centres of most large galaxies.