Atomic T Tauri disk winds heated by ambipolar diffusion

Abstract

We summarize results on the thermal and ionization structure of self-similar, magnetically-driven, atomic disk winds heated by ambipolar diffusion. We improve upon earlier work by Safier by considering (1) new MHD solutions consistent with underlying cold keplerian disk equilibrium, (2) a more accurate treatment of the micro-physics, and (3) predictions for spatially resolved forbidden line emission (maps, long-slit spectra). The temperature plateau $\simeq 10^4$ K found earlier is recovered, but ionization fractions are revised downward by a factor of 10, due to previous omission of thermal speeds in ion-neutral momentum-exchange rates. The physical origin of the temperature plateau is outlined. Predictions are then compared with T~Tauri star observations, with emphasis on the necessity of suitable beam convolution. Jet widths and variations in line profiles with distance and line tracer are well reproduced. However, predicted maximum velocities are too high, total densities too low, and the low-velocity [OI] component is too weak. Denser, slower MHD winds from warm disks might resolve these discrepancies.

To apear in Rev Mex A A, special issue : Emission lines from jet flows, ed . L. Binette and W. Henney, 2001

References in corpus (7)

• HST/STIS spectroscopy of the optical outflow from DG Tau: structure and kinematics on sub-arcsecond scales
• Magneto-Centrifugal Launching of Jets from Accretion Disks. I: Cold Axisymmetric Flows
• Irradiated Herbig-Haro Jets in the Orion Nebula and Near NGC 1333
• A disk-wind model with correct crossing of all MHD critical surfaces
• Magnetic propeller outflows
• Hubble Space Telescope Images of the Subarcsecond Jet in DG Tau
• The Current Star Formation Rate of the Local Universe