The post Big Bang revelead

(Université de Genève) One billion year after the Big Bang, the Universe is observed to be reheated, and hydrogen is again ionize. How has this important transformation, named cosmic reionization, been possible? Astronomers have long thought that galaxies were responsible for this phenomenon. Today, researchers have largely validated this hypothesis. They have indeed discovered a compact galaxy emitting a large number of ionizing photons, which are responsible for this transformati