Ratio of the jet power to the bolometric luminosity of the disk during accretion onto a black hole

Abstract

Disk accretion onto black holes is accompanied by collimated outflows (jets). In active galactic nuclei (AGN), the kinetic energy flux of the jet (jet power or kinetic luminosity) may exceed the bolometric luminosity of the disk by a few orders of magnitude. This may be explained in the framework of the so-called “cold” disk accretion when the only source of the AGN energy is the energy released by accretion. The radiation from the disk is suppressed because the disk wind carries out almost all the angular momentum and the gravitational energy of the accreting material. In this paper, we calculate the “unavoidable” radiation from the “cold” disk and the ratio of the kinetic energy power of the outflow to the bolometric luminosity of the accretion disk around a super massive black hole in the framework of the Shakura and Sunyaev paradigm of an optically thick [Formula: see text]-disk. The exploration of the Fundamental Plane of Black Holes allows us to obtain equations that define the bolometric luminosity and the ratio of the luminosities as functions of the black hole mass and accretion rate. The application of our equations in the case of the M87 jet demonstrates good agreement with observations. In the case of Sgr A*, these equations allow us to predict the kinetic energy flux from the disk around the Galactic supermassive black hole.