  Star-forming galaxies like the Milky Way are surrounded by a hot gaseous halo
at the virial temperature - the so-called galactic corona - that plays a
fundamental role in their evolution. The interaction between the disc and the
corona has been shown to have a direct impact on accretion of coronal gas onto
the disc with major implications for galaxy evolution. In this work, we study
the gas circulation between the disc and the corona of star-forming galaxies
like the Milky Way. We use high-resolution hydrodynamical N-body simulations of
a Milky Way-like galaxy with the inclusion of an observationally-motivated
galactic corona. In doing so, we use SMUGGLE, an explicit interstellar medium
(ISM) and stellar feedback model coupled with the moving-mesh code Arepo. We
find that the reservoir of gas in the galactic corona is sustaining star
formation: the gas accreted from the corona is the primary fuel for the
formation of new stars, helping in maintaining a nearly constant level of cold
gas mass in the galactic disc. Stellar feedback generates a gas circulation
between the disc and the corona (the so-called galactic fountain) by ejecting
different gas phases that are eventually re-accreted onto the disc. The
accretion of coronal gas is promoted by its mixing with the galactic fountains
at the disc-corona interface, causing the formation of intermediate temperature
gas that enhance the cooling of the hot corona. We find that this process acts
as a positive feedback mechanism, increasing the accretion rate of coronal gas
onto the galaxy.
