Powerful Radio Sources as Probes of Black Hole Physics

TL;DR

This paper investigates powerful radio sources to understand black hole physics, revealing that outflow energies are a small, consistent fraction of black hole mass and exploring implications for black hole growth, mergers, and feedback mechanisms.

Contribution

It provides empirical analysis of radio source outflows, linking their energies and lifetimes to black hole properties and proposing explanations involving black hole spin, mergers, and feedback.

Findings

Outflow energy is a small, consistent fraction of black hole mass.

Outflow lifetime depends primarily on directed kinetic energy luminosity.

Results suggest possible black hole spin energy extraction or merger-related phenomena.

Abstract

Powerful jetted radio sources for which the luminosity in directed kinetic energy has been empirically determined, independent of assumptions, are considered. The total outflow lifetime of each source determined in the context of detailed cosmological studies was found to depend only upon the luminosity in directed kinetic energy ($L$). The distributions of $L$, total outflow lifetime, and total outflow energy each have a broad range of values, as do the supermassive black hole masses. The total outflow energy relative to the black hole mass is a small number with a small dispersion. Three explanations of these remarkable results are considered. This could indicate (1) the efficiencies with which black hole irreducible mass is increased and spin mass energy is extracted during the outflow event, (2) that the merger of two supermassive black holes occurs over a timescale commensurate with the independently determined outflow lifetime and that these mergers lead to the production of the low-frequency gravitational wave background, or (3) that feedback shuts off black hole accretion due to energy injected into the ambient medium.