Abstract

I will present results on the properties of faint galaxies and AGN in the early Universe, building upon samples identified using Wide Field Slitless Spectroscopy with NIR Cam on the James Webb Space Telescope (JWST). This mode effectively turns JWST into an efficient redshift machine ideal to map out galaxy over-density. In my talk, I will focus on two topics: 1) The impact of galaxies and AGN on the reionization of the Universe, directly measured by mapping out the correlation between galaxies and ionized regions with quasar and galaxy transmission spectroscopy, and 2) The nature of broad Hα line-selected AGN (the so-called Little Red Dots) that JWST has uncovered in the first few Gyr, including new results based on the deep NIR Cam grism spectroscopy of their large-scale environments, deep high resolution spectroscopy unveiling the prevalence of dense absorbing gas and resolved Lyman-alpha mapping of the circumgalactic medium with VLT /MUSE. Finally, I will synthesize what these observations are learning us in the context of galaxy – SMBH co-evolution, SMBH formation and their role in cosmic reionization.