Accretion-driven winds of T Tauri stars:A new generation of models with self-consistentcoronal heating and MHD turbulence

摘要

Classical T Tauri stars are observed to be surrounded by both accretion flows and somekind of wind or jet-like outflow. There are several possible explanations of how and where theoutflows arise, including disk winds, X-winds, impulsive (CME-like) ejections, and stellar winds.Recent work by Matt and Pudritz has suggested that if there is a stellar wind with a mass loss rateabout 0.1 times the accretion rate, the wind may be able to carry away enough angular momentumto keep the stars from being spun up unrealistically by accretion. In this presentation, I showa preliminary set of theoretical models of accretion-driven winds from the polar regions of TTauri stars. These models are based on recently published self-consistent simulations of the Sun'scoronal heating and wind acceleration. In addition to the convection-driven MHD turbulence (whichdominates in the solar case), I add a source of wave energy at the photosphere that is driven bythe impact of plasma in neighboring flux tubes undergoing magnetospheric accretion. This addedenergy, which is determined quantitatively from the far-field theory of MHD wave generation, seemsto be enough to produce T Tauri-like mass loss rates. It is still uncertain, though, whether it is enoughto solve the T Tauri angular momentum problem.