  We present a new semi-analytical model of the population of satellite
galaxies of the Milky Way, aimed at estimating the effect of the geometry of
reionization at galaxy scale on the properties of the satellites. In this model
reionization can be either: (A) externally-driven and uniform, or (B)
internally-driven, by the most massive progenitor of the Milky Way. In the
latter scenario the propagation of the ionisation front and photon dilution
introduce a delay in the photo-evaporation of the outer satellites' gas with
respect to the inner satellites. As a consequence, outer satellites experience
a longer period of star formation than those in the inner halo. We use simple
models to account for star formation, the propagation of the ionisation front,
photo-evaporation and observational biases. Both scenarios yield a model
satellite population that matches the observed luminosity function and
mass-to-light ratios. However, the predicted population for scenario (B) is
significantly more extended spatially than for scenario (A), by about 0.3 dex
in distance, resulting in a much better match to the observations. The survival
of the signature left by the local UV field during reionization on the radial
distribution of satellites makes it a promising tool for studying the
reionization epoch at galaxy scale in the Milky Way and nearby galaxies
resolved in stars with forthcoming large surveys.
