Radiatively inefficient magnetohydrodynamic accretion-ejection structures

We present magnetohydrodynamic simulations of a resistive accretion disk continuously launching trans-magnetosonic, collimated jets. We time-evolve the full set of magnetohydrodynamic equations but neglect radiative losses in the energetics (radiatively inefficient). Our calculations demonstrate that a jet is self-consistently produced by the interaction of an accretion disk with an open, initially bent large-scale magnetic field. A constant fraction of heated disk material is launched in the inner equipartition disk regions, leading to the formation of a hot corona and a bright collimated, superfast magnetosonic jet. We illustrate the complete dynamics of the hot'' near-steady state outflow (where thermal pressure similar or equal to magnetic pressure) by showing force balance, energy budget, and current circuits. The evolution to this near-stationary state is analyzed in terms of the temporal variation of energy fluxes controlling the energetics of the accretion disk. We find that unlike advection-dominated accretion flow, the energy released by accretion is mainly sent into the jet rather than transformed into disk enthalpy. These magnetized, radiatively inefficient accretion-ejection structures can account for underluminous thin disks supporting bright fast collimated jets as seen in many systems displaying jets (for instance, M87).