Atomic T Tauri disk winds heated by ambipolar diffusion - II. Observational tests

Thermal and ionization structures of self-similar, magnetically-driven disk winds obtained in a companion paper (Garcia et al. 2001) are used to compu te a series of jet synthetic observations. These include spatially resolved forbidden line emission maps, long-slit spectra, as well as line ratios. L ine profiles and jet widths appear to be good tracers of the wind dynamics and collimation, whereas line ratios essentially trace gas excitation condi tions. All the above diagnostics are confronted to observations of T Tauri star microjets. Convolution by the observing beam is shown to be essential for a meaningful test of the models. We find that jet widths and qualitativ e variations in line profiles with both distance and line tracers are well reproduced. A low-velocity [O I] component is also obtained, originating fr om the disk wind base. However, this component is too weak, predicted maxim um velocities are too high and electronic and total densities are too low. Denser and slower magnetized winds, launched from disks with warm chromosph eres, might resolve these discrepancies.