  We have carried out a spatio-kinematic study of the outflow from the
classical T Tauri star DG Tau using the Space Telescope Imaging Spectrograph
(STIS) on board the Hubble Space Telescope (HST). A series of seven spatially
offset long-slit spectra spaced by 0.07'' were obtained along the axis of the
outflow to build up a 3-D intensity-velocity ``cube'' in various forbidden
emission lines (FELs) and Ha. Here we present high spatial resolution synthetic
line images close to the star in distinct radial velocity intervals (from ~ +50
km/s to ~ -450 km/s in four bins, each ~ 125 km/s wide). The lowest velocity
emission is also examined in finer detail (from +60 km/s to -70 km/s in five
bins ~ 25 km/s wide). We have found that the highest velocity and most highly
collimated component, i.e. the jet, can be traced from DG Tau to a distance D ~
0.7''. The jet is on the axis of a pear-shaped limb-brightened bubble which
extends between 0.4'' and 1.5'' from the source and which we interpret as a bow
shock. Other condensations are seen close to the star indicating ongoing
temporal variations in the flow. The low-velocity component of the outflow is
found to be spatially wide close to the source (~ 0.2'' at D=0.2''), in
contrast to the high velocity jet (width <~ 0.1''). We have also found evidence
to suggest that the density increases longitudinally with proximity to the
source and also laterally towards the flow axis. Thus, at least in the case of
DG Tau, the flow becomes gradually denser as it increases in velocity and
becomes more collimated. Our observations show a continous bracketing of the
higher speed central flow within the lower speed, less collimated, broader
flow, down to the lowest velocity scales. This suggests that the low and high
velocity FELs in the highly active T Tauri star DG Tau are intimately related.
