Optically Quiet Quasars – Radio and Optical Investigations

Extract

The activity in the nuclei of bright galaxies could arise from a number of sources: they may contain compact variable radio sources, they may be strong IR/optical/X–ray continuum sources, or they may have strong emission lines. Usually but not always these properties go together as in radio loud quasars. However, there appears to exist a class of objects which resemble quasars in radio structure and brightness – have strong flat spectrum cores but appear fainter than would be suggested by their radio brightness – unidentified on sky surveys (Zensus & Porcas, 1985, in J. Dyson, ed, AGN). These are called ‘optically quiet quasars’ (OQQs).