  The results of a wide-field survey of the Sculptor dwarf spheroidal galaxy
are presented. Our aims were to obtain an accurate map of the outer structure
of Sculptor, and to determine the level of interaction between this system and
the Galaxy. Photometry was obtained in two colours down to the magnitude limits
of V=20 and I=19, covering a 3.1 times 3.1 square deg area centred on Sculptor.
The resulting colour-magnitude data were used as a mask to select candidate
horizontal branch and red giant branch stars for this system. Previous work has
shown that the red horizontal branch (HB) stars are more concentrated than the
blue HB stars. We have determined the radial distributions of these two
populations and show that the overall Sculptor density profile is well
described by a two component model based on a combination of these radial
distributions. Additionally, spectra of the Ca ii triplet region were obtained
for over 700 candidate red giant stars over the 10 square deg region using the
2dF instrument on the Anglo-Australian Telescope. These spectra were used to
remove foreground Galactic stars based on radial velocity and Ca ii triplet
strength. The final list of Sculptor members contained 148 stars, seven of
which are located beyond the nominal tidal radius. Both the photometric and
spectroscopic datasets indicate no significant extra-tidal structure. These
results support at most a mild level of interaction between this system and the
Galaxy, and we have measured an upper mass limit for extra-tidal material to be
2.3 +/- 0.6% of the Sculptor luminous mass. This lack of tidal interaction
indicates that previous velocity dispersion measurements (and hence the amount
of dark matter detected) in this system are not strongly influenced by the
Galactic tidal field.
