On the reionization history of the Milky Way

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 photoevaporation 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 then report on the progress of the PICON project (Photo-Ionization of CONstrained simulations of the local group): we perform a radiative postprocessing of high resolution hydrodynamical simulations of the Milky Way and M31 from the CLUES project (http://www.clues-project.org) project, in order to study the in detail the reionization of local group...