摘要
We discuss transportation and redistribution of energy and angular momentum in the magnetic connection(MC) process and Blandford-Payne(BP) process.MC results in readjusting the interior viscous torque,and its effects are operative not only in but also beyond the MC region.The BP process is invoked to transfer the "excessive" angular momentum from an accretion disc.In addition,we derive a criterion for the interior viscous torque to resolve the puzzle of the overall equilibrium of angular momentum in disc accretion.It turns out that the efficiency of BP at extracting angular momentum and the intensity of the outflow are required to be greater than some critical values.
We discuss transportation and redistribution of energy and angular momentum in the magnetic connection(MC) process and Blandford-Payne(BP) process.MC results in readjusting the interior viscous torque,and its effects are operative not only in but also beyond the MC region.The BP process is invoked to transfer the "excessive" angular momentum from an accretion disc.In addition,we derive a criterion for the interior viscous torque to resolve the puzzle of the overall equilibrium of angular momentum in disc accretion.It turns out that the efficiency of BP at extracting angular momentum and the intensity of the outflow are required to be greater than some critical values.
基金
supported by the National Natural Science Foundation of China (Grant No. 10873005)
the Research Fund for the Doctoral Program of Higher Education (Grant No. 200804870050)
the National Basic Research Program of China (Grant No. 2009CB824800)
