A common approach for the interpretation of such astrophysical objects as active galactic nuclei (AGN) and young stellar objects (YSOs) are the MHD models of collimated outflows, driven by accretion disks in the proximity of a central attractor. In this study we present a series of time dependent axisymmetric numerical simulations of a jet-launching accretion disk, where both the outflow and the disk itself are treated consistently. In particular the issue of entropy generation due to anomalous transport coefficients is being addressed. The relevance of Ohmic and viscous heating is examined, in the context of its influence in the mass loading process. Since the ejection rates determine to a great extent the dynamics of the out-flowing plasma, thermal effects play too much of an important role to be ignored. We discuss the characteristics of the numerical solutions and establish the relationship between heating and various important parameters of the ouflows (magnetic lever arm, ejection efficiencies, mass fluxes etc.) that can be then cross-checked with observations.

On the Generation of Entropy in Jet-Launching Disks

TZEFERACOS, Petros;FERRARI, Attilio;MIGNONE, ANDREA;MASSAGLIA, Silvano
2010-01-01

Abstract

A common approach for the interpretation of such astrophysical objects as active galactic nuclei (AGN) and young stellar objects (YSOs) are the MHD models of collimated outflows, driven by accretion disks in the proximity of a central attractor. In this study we present a series of time dependent axisymmetric numerical simulations of a jet-launching accretion disk, where both the outflow and the disk itself are treated consistently. In particular the issue of entropy generation due to anomalous transport coefficients is being addressed. The relevance of Ohmic and viscous heating is examined, in the context of its influence in the mass loading process. Since the ejection rates determine to a great extent the dynamics of the out-flowing plasma, thermal effects play too much of an important role to be ignored. We discuss the characteristics of the numerical solutions and establish the relationship between heating and various important parameters of the ouflows (magnetic lever arm, ejection efficiencies, mass fluxes etc.) that can be then cross-checked with observations.
2010
9th International Conference of the Hellenic Astronomical Society
Athens
September 20-24, 2009
Proceedings of the 9th International Conference of the Hellenic Astronomical Society
Tsinganos, Kanaris; Hatzidimitriou, Despina; Matsakos, Titos
155
159
9781583817285
Tzeferacos, P.; Ferrari, A.; Mignone, A.; Zanni, C.; Bodo, G.; Massaglia, S.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/87400
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