  One of the best-studied jets from all young stellar objects is the jet of DG
Tau, which we imaged in the FUV with HST for the first time. These high spatial
resolution images were obtained with long-pass filters and allow us to
construct images tracing mainly molecular hydrogen and C IV emission. We find
that the H2 emission appears as a limb-brightened cone with additional emission
close to the jet axis. The length of the rims is about 0.3 arcsec or 42 AU
(proj.) before their brightness strongly drops, and the opening angle is about
90 deg. Comparing our FUV data with near-IR data we find that the fluorescent
H2 emission likely traces the outer, cooler part of the disk wind while an
origin of the H2 emission in the surface layers (atmosphere) of the (flared)
disk is unlikely. Furthermore, the spatial shape of the H2 emission shows
little variation over six years which suggests that the outer part of the disk
wind is rather stable and probably not associated with the formation of
individual knots. The C IV image shows that the emission is concentrated
towards the jet axis. We find no indications for additional C IV emission at
larger distances, which strengthens the association with the X-ray emission
observed to originate within the DG Tau jet.
