What can cause a galactic fountain?

A galactic fountain is primarily caused by the combined effects of supernova explosions and stellar winds from massive stars. These energetic events eject gas and dust from the galactic disk into the galaxy's halo, creating outflows that can rise and fall due to gravitational forces and galactic dynamics. Additionally, the cooling and subsequent condensation of the ejected material can lead to the formation of new stars, contributing to the cycle of star formation within the galaxy.