Radiatively Inefficient Magnetohydrodynamic Accretion‐Ejection Structures

We present magnetohydrodynamic simulations of a resistive accretion diskcontinuously launching transmagnetosonic, collimated jets. We time-evolve thefull set of magnetohydrodynamic equations, but neglect radiative losses in theenergetics (radiatively inefficient). Our calculations demonstrate that a jetis self-consistently produced by the interaction of an accretion disk with anopen, initially bent large-scale magnetic field. A constant fraction of heateddisk material is launched in the inner equipartition disk regions, leading tothe formation of a hot corona and a bright collimated, super-fastmagnetosonicjet. We illustrate the complete dynamics of the ``hot'' near steady-stateoutflow (where thermal pressure $\simeq$ magnetic pressure) by showing forcebalance, energy budget and current circuits. The evolution to this nearstationary state is analyzed in terms of the temporal variation of energyfluxes controlling the energetics of the accretion disk. We find that unlikeadvection-dominated accretion flow, the energy released by accretion is mainlysent into the jet rather than transformed into disk enthalpy. These magnetized,radiatively inefficient accretion-ejection structures can account forunder-luminous thin disks supporting bright fast collimated jets as seen inmany systems displaying jets (for instance M87).