A model for electromagnetic extraction of rotational energy and formation of accretion-powered jets in radio galaxies^*

Max-Planck-Institut für Astronomie, 69117 Heidelberg, Germany

Corresponding author: hujeirat@mpia-hd.mpg.de

Received: 17 July 2003
Accepted: 21 November 2003

Abstract

A self-similar solution for the 3D axi-symmetric radiative MHD equations is presented, which revisits the formation and acceleration of accretion-powered jets in AGNs and microquasars. The model relies primarily on electromagnetic extraction of rotational energy from the disk plasma and forming a geometrically thin super-Keplerian layer between the disk and the overlying corona. The outflowing plasma in this layer is dissipative, two-temperature, virial-hot, advective and electron-proton dominated. The innermost part of the disk in this model is turbulent-free, sub-Keplerian rotating and advective-dominated. This part ceases to radiate as a standard disk, and most of the accretion energy is converted into magnetic and kinetic energies that go into powering the jet. The corresponding luminosities of these turbulent-truncated disks are discussed. In the case of a spinning black hole accreting at low accretion rates, the Blandford-Znajek process is found to modify the total power of the jet, depending on the accretion rate.