Daniel Ceverino - October 14, 2016 Galaxy Formation through the dark ages until today This talk will cover two different topics related to galaxy formation at different times in the history of the Universe. Using simulations of galaxy formation, we study the transformation of a dispersion-dominated galaxy into a rotation-dominated, but turbulent disc at z~1.5. During the subsequent evolution of the disc, the level of velocity dispersion decreases with time and the gas settles in an extended and quiet gaseous disc, typical of late-type galaxies in the local Universe (z~0). In the second part of the talk, I will present first results of the FirstLight project. This project aims to follow the formation of the first galaxies in the early Universe. Upon completion, the FirstLight dataset will generate a mock survey of galaxies between redshifts 6 and 15. This survey will make predictions about the properties of the primeval galaxies that would be observed by future deep surveys with the James Webb Space Telescope and Extremely Large Telescopes. In the pilot study, we follow the formation of a dwarf galaxy with an UV absolute magnitude of M1500=-13 at redshift 8, a likely candidate for driving the reionization of the Universe.