3C 216: A Powerful FR II Seyfert 1 Galaxy

Abstract

3C 216 has a weak accretion flow luminosity, well below the Seyfert 1/QSO dividing line, weak broad emission lines (BELs), and powerful radio lobes. As a consequence of the extreme properties of 3C 216, it is the most convincing example known of an FR II radio source that is kinetically dominated: the jet kinetic luminosity, Q, is larger than the total thermal luminosity (IR to X-ray) of the accretion flow, Lbol. Using three independent estimators for the central black hole mass, we find that the jet in 3C 216 is very super-Eddington, 3.3LEdd < < 10LEdd, where is the long-term time-averaged Q(t), calculated at 151 MHz. It is argued that 3C 216 satisfies the contemporaneous kinetically dominated condition, R(t) ≡ Q(t)/Lbol(t) > 1, either presently or in the past, based on the rarity of Lbol > LEdd quasars. The existence of an R(t) > 1 AGN is a strong constraint on the theory of the central engine of FR II radio sources.