Le 16 février 2018
De 10h30 à 12h00
Pratika Dayal
RUG, Groningen
Galaxy formation in the first billion years mark a time of great upheaval in the history of the Universe: as the first sources of light, these galaxies ended the ‘cosmic dark ages’ and produced the first photons that could break apart the hydrogen atoms suffusing all of space starting the process of cosmic reionization. As the earliest building blocks, the shapeless ellipticals galaxies that formed in the first billion years also determine the physical properties of all subsequent galaxy populations. At the forefront of astronomical research, the past few years have seen cutting-edge instruments provide tantalising glimpses of such galaxies chaotically assembling in an infant Universe. I will show how this data has provided an unprecedented opportunity to pin down the reionization state of the Universe (at least in its last stages), understand their physical properties, and study the key physics driving their formation and evolution. Finally, I will try to give a flavour of how the assembly of early galaxies, accessible with the forthcoming James Webb Space Telescope and the associated reionization history, can provide a powerful testbed for Warm Dark Matter models.