Radiatively Inefficient Magnetohydrodynamic Accretion-Ejection Structures
Abstract
We present magnetohydrodynamic simulations of a resistive accretion disk continuously launching transmagnetosonic, 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~=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).
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 2004
- DOI:
- 10.1086/380441
- arXiv:
- arXiv:astro-ph/0310322
- Bibcode:
- 2004ApJ...601...90C
- Keywords:
-
- Accretion;
- Accretion Disks;
- Galaxies: Jets;
- ISM: Jets and Outflows;
- Magnetohydrodynamics: MHD;
- Astrophysics
- E-Print:
- Astrophysical Journal (in press). Figures are missing due to file size restrictions. To have the complete paper just click on http://www-laog.obs.ujf-grenoble.fr/~fcasse/MS56638.pdf