The VMC Survey - X. Cepheids, RR Lyrae stars and binaries as probes of
  the Magellanic System's structure
  The VMC survey is obtaining multi-epoch photometry in the Ks band of the
Magellanic System down to a limiting magnitude of Ks ~ 19.3 for individual
epoch data. The observations are spaced in time such as to provide optimal
sampling of the light curves for RR Lyrae stars and for Cepheids with periods
up to 20-30 days. We present examples of the Ks-band light curves of Classical
Cepheids and RR Lyrae stars we are obtaining from the VMC data and outline the
strategy we put in place to measure distances and infer the System
three-dimensional geometry from the variable stars. For this purpose the
near-infrared Period-Luminosity, Period-Wesenheit, and Period-Luminosity-Colour
relations of the system RR Lyrae stars and Cepheids are used. We extensively
exploit the catalogues of the Magellanic Clouds' variable stars provided by the
EROS-2 and OGLE III/IV microlensing surveys. By combining these surveys we
present the currently widest-area view of the Large Magellanic Cloud as
captured by the galaxy Cepheids, RR Lyrae stars and binaries. This reveals the
full extent of the main structures (bar/s - spiral arms) that have only been
vaguely guessed before. Our work strengthens the case for a detailed study of
the Large Magellanic Cloud three-dimensional geometry.
