The shell game: a panoramic view of Fornax
  We present a panoramic study of the Fornax dwarf spheroidal galaxy, using
data obtained as part of the VLT Survey Telescope (VST) ATLAS Survey. The data
presented here -- a subset of the full survey -- uniformly cover a region of 25
square degrees centred on the galaxy, in $g$, $r$ and $i$-bands. This large
area coverage reveals two key differences to previous studies of Fornax. First,
data extending beyond the nominal tidal radius of the dwarf highlight the
presence of a second distinct red giant branch population. This bluer red giant
branch appears to be coeval with the horizontal branch population. Second, a
shell structure located approximately 1.4 degrees from the centre of Fornax is
shown to be a mis-identified background overdensity of galaxies. This last
result casts further doubt on the hypothesis that Fornax underwent a gas-rich
merger in its relatively recent past.
