Probing the Physics of Supermassive Black Holes with Powerful Radio Sources*

Supermassive black holes associated with the production of very powerful dual jetted outflows have unique properties that make them suitable to probe the physics of the host supermassive black hole. Detailed studies of a sample of about 100 such sources, referred to as FRIIb radio sources, also known as classical doubles, led to several new and important results. These results include empirically determined, model-independent  relationships between the supermassive black hole mass and: (i) the total jetted outflow lifetime, (ii) the total energy carried by the jetted outflow during the source lifetime, and (iii) the luminosity in directed kinetic energy carried by the jetted outflow. The relationship between each of these quantities and the mass of the host supermassive black hole will be discussed. For example, it has been determined that the total energy carried by the dual jetted outflow over the source lifetime is a constant fraction of the supermassive black hole mass. 

The results indicate that there is significant overlap between FRIIb source properties and those required for a population of supermassive black holes to produce the recently detected low-frequency gravitational wave background. The FRIIb source characteristics will be presented, and compared with those required of the sources that are responsible for the production of the gravitational wave background. For example, theoretical calculations published by other groups indicate that the sources that produce the low-frequency gravitational wave background have: (i) supermassive black hole masses of about 100 million to 10 billion times that of the sun; (ii) total lifetimes of about 30 million years; and (iii) redshifts between about zero and three. These are precisely the characteristics of  the FRIIb sources discussed above. 

The results also have implications for: (i) the mechanism that leads to the production of the dual jetted outflows, and (ii) the application of observations to obtain and study the irreducible and rotational supermassive black hole mass components relative to the total black hole mass. These topics will be presented and discussed with a focus on the source properties suggesting that they are major contributors to the recently detected low-frequency gravitational wave background.