One of the open problems in astrophysical research is the formation and evolution of galaxies. To tackle this problem, EU-funded scientists performed simulations of the so-called galactic fountain.
In galaxies, like our Milky Way galaxy, massive stars produce significant winds that blow out of the disc of the galaxy. Some of these stars may explode, sending most of their material rich in metals up and out of the galaxy disc. This hot, metal-enriched gas mills about and cools down before pouring down on the galaxy. Astrophysicists call this phenomenon galactic fountain.
Further details: From the galactic fountain to single stars