  The asteroid (4) Vesta, parent body of the Howardite-Eucrite-Diogenite
meteorites, is one of the first bodies that formed, mostly from
volatile-depleted material, in the Solar System. The Dawn mission recently
provided evidence that hydrated material was delivered to Vesta, possibly in a
continuous way, over the last 4 Ga, while the study of the eucritic meteorites
revealed a few samples that crystallized in presence of water and volatile
elements. The formation of Jupiter and probably its migration occurred in the
period when eucrites crystallized, and triggered a phase of bombardment that
caused icy planetesimals to cross the asteroid belt. In this work, we study the
flux of icy planetesimals on Vesta during the Jovian Early Bombardment and,
using hydrodynamic simulations, the outcome of their collisions with the
asteroid. We explore how the migration of the giant planet would affect the
delivery of water and volatile materials to the asteroid and we discuss our
results in the context of the geophysical and collisional evolution of Vesta.
In particular, we argue that the observational data are best reproduced if the
bulk of the impactors was represented by 1-2 km wide planetesimals and if
Jupiter underwent a limited (a fraction of au) displacement.
