3C 216: A Powerful FRII Seyfert 1 Galaxy

Abstract

3C 216 has a weak accretion flow luminosity, well below the Seyfert1/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, $L_{bol}$. Using three independent estimators for the central black hole mass, we find that the jet in 3C 216 is very super-Eddington, $3.3 L_{Edd}<\bar{Q}< 10 L_{Edd}$, where $\bar{Q}$ is the long term time averaged $Q(t)$, calculated at 151 MHz. It is argued that 3C 216 satisfies the contemporaneous kinetically dominated condition, $R(t)\equiv Q(t)/L_{bol}(t)>1$, either presently or in the past based on the rarity of $L_{bol}>L_{Edd}$ quasars. The existence of $R(t)>1$ AGN is a strong constraint on the theory of the central engine of FRII radio sources.