Anna de Graaff

A new view of the red and distant Universe from JWST/NIRSpec

Abstract: In its three years of science operations, JWST has revolutionized our understanding of the early Universe. Arguably the most impressive leap forward has come from the NIRSpec instrument, providing a detailed view of the physical processes – star formation, feedback, and the growth of massive black holes – that shaped the faintest, reddest, and most distant galaxies. Among a wealth of discoveries, one overarching surprise has emerged: galaxies in the early Universe formed and matured extremely fast. Massive galaxies with old stellar populations exist already in the first billion years of the Universe, with some showing morphologies reminiscent of our own Milky Way, while others host unexpectedly massive black holes. The potential implications on galaxy formation models are profound, as current models struggle to reproduce such rapid galaxy assembly. I will present an overview of key extragalactic surveys from JWST/NIRSpec, focusing on the major discoveries that they have enabled and the challenges that remain.