  Using the UVES echelle spectrograph at the ESO VLT we obtained
two-dimensional high-resolution (R = 50 000) spectra of the edge-on disk
objects HH30*, HK Tau B, and HV Tau C. For comparison purposes we also observed
with the same equipment both the classical T Tauri star HL Tau and the active
late-type star LDN 1551-9. The spectra of all three observed edge-on disks
consist of a T Tauri emission and absorption line spectrum with superimposed
jet emission lines. Analysis of the spectra confirmed that the disks are
completely opaque at visible wavelengths and that light from the central
objects reaches us only via scattering layers above and below the disk planes.
The central objects of our targets were found to be normal T Tauri stars
showing moderate but different amounts of veiling of their photospheric
spectra, indicating different accretion rates or evolutionary stages. We
suggest that all classical T Tauri stars (CTTSs) show this observed morphology
when viewed edge-on. Part of the jet emission from edge-on systems is directly
visible to us in the forbidden lines as well as in Halpha and He I, a finding
which contradicts the present paradigm of a pure magnetospheric accretion
origin for the formation of hydrogen and helium emission lines in moderately
active CTTSs. From a comparison with those Taurus-Auriga CTTSs for which the
inclination is reliably known, we conclude that the view angle of CTTS systems
is one of the key parameters governing apparent Halpha emission strength in the
T Tauri class. We discuss the various possible formation regions for the Na I D
lines and show that profiles similar to observed ones can be formed at the base
of the disk wind.
