The Origin of Jets from Young Stars: Steady State Disk Wind Models Confronted to Observations

International audienceWe discuss in this contribution constraints on the origin of mass-loss from young stars brought by recent observations at high angular resolution (0.1" = 14 AU) of the inner regions of winds from T Tauri stars. Jet widths and collimation scales, the large extent of the velocity profile as well as the detection of rotation signatures agree with predictions from extended ( R e >= 1 AU) magneto-centrifugal disk wind ejection models. Detected poloidal and toroidal velocities imply large ejection efficiencies (xi ~= 0.05, lambda ~= 10), suggesting that thermal gradients (originating in an accretion heated disk corona for example) play an important role in accelerating the flow