Magnetized accretion-ejection structures IV. Magnetically-driven jets fromresistive, viscous, Keplerian discs

We present steady-state calculations of self-similar magnetized accretion d iscs driving cold, adiabatic, non-relativistic jets. For the first time, bo th the magnetic torque due to the jets and a turbulent "viscous" torque are taken into account. This latter torque allows a dissipation of the accreti on power as radiation at the disc surfaces, while the former predominantly provides jets with power. The parameter space of these structures has been explored. It is characteri zed by four free parameters, namely the disc aspect ratio and three MHD tur bulence parameters, related to the anomalous magnetic diffusivities and vis cosity. It turns out that launching cold jets from thin, dissipative discs implies anisotropic turbulent dissipation. Jets that asymptotically reach a high Alfvenic Mach number are only produced by weakly dissipative discs. We obtained general analytical relations between disc and jet quantities th at must be fulfilled by any steady-state model of cold jets, launched from a large radial extension of thin discs. We also show that such discs cannot have a dominant viscous torque. This is because of the chosen geometry, im posing the locus of the Alfven surface. Some observational consequences of these cold magnetized accretion-ejection structures are also briefly discussed.