Thermal conduction effects on the accretion-ejection mechanism. I. Accretion flow investigation.
REZGUI G., MARZOUGUI H., WOODRING J., SVOBODA J. and LILI T.
Abstract (from CDS):
Understanding the accretion of matter around compact objects such as young stars or black holes remains one of the most interesting problems in astrophysics. Recent observations detected the accretion of matter of several young stars from their circumstellar disk and proposed the existence of the X-ray emission at very high temperature. The hot gases surrounding these systems are likely to proceed under the collisionless regime, which indicates that the thermal conduction has a relevant contribution in the transport of energy along the accretion disks. Notwithstanding its importance, this physical ingredient is largely neglected in previous time-dependent studies of accretion-ejection structure. More research is still necessary before obtaining a complete picture of such a phenomenon. In this series, we have included the three nonideal effects together, viscosity, resistivity, and thermal conduction, to explore the physical mechanism of the disk-jet system. We carry out extensive time-dependent simulations of the accretion disk and jet using the PLUTO code. The mean field approach is used in this work by taking into account the evolution of the disk and jet simultaneously. We show in this first paper how the thermal conduction plays a crucial role in the accretion disk dynamics by presenting a detailed discussion of its effects on the evolution of basic facets of the inflow properties with a special emphasis on the equatorial plane and disk surface. Our model also shows strong indications of the ejection efficiency improvement in the presence of thermal conduction.