The James Webb Space Telescope has opened an unprecedented window into galaxy formation in the very high-redshift Universe, creating new excitement around the first billion years of cosmic history (z>6). In this talk I will highlight related advances and prospects for the study of Reionization and early galaxy formation, and our attempts to connect the dots between our prior knowledge and new high-redshift discoveries. First, I will recall the ingredients for Reionization of the intergalactic medium as driven by galaxies, and will explain how the latest observations and simulations enable us to better grasp the relationship between ionization and galaxy formation. Then, I will make the case for leveraging these results alongside upcoming IGM probes (such as HI tomography with the Square Kilometer Array) to probe galaxy formation in the first billion years.
Second, I will discuss tensions between galaxy observations and cosmological simulations beyond z=8. For this purpose, I will focus on the relationship between forming early massive black holes and quenching massive galaxies in simulations, and attempting to explain observations of massive quenched galaxies at z>4.
Contact local & organisation: Frédéric GALLIANO
DAp