Final Report Summary - GASAROUNDGALAXIES (Studying the gas around galaxies with the Multi Unit Spectroscopic Explorer and hydrodynamical simulations) The evolution of galaxies is thought to be driven by the infall of gas, which fuels further star formation. However, the energy released by exploding young stars and by gas spiraling into black holes can drive the gas back out of the galaxies, thus regulating their growth. Our understanding of these processes is limited on the one hand by the difficulty of observing the dilute gas around galaxies and on the other hand by our inability to model all the relevant processes. This project took advantage of the new MUSE instrument at the Very Large Telescope to infer the properties of the gas near galaxies. Newly developed computational methods and supercomputers were used to simulate the gas flows in and around galaxies. The simulations came in two flavours: the EAGLE simulations of volumes large enough to contain a fair sample of the galaxy population and higher-resolution zooms of smaller volumes.