E. Egami

Abstract Early galaxies form through dark matter and gas assembly, evolving into dynamically hot, chaotic structures driven by mergers and feedback. By contrast, remarkably smooth, rotating disks are observed in massive galaxies only 1.4 billion years after the Big Bang, implying rapid dynamical evolution. Probing this evolution mechanism necessitates studies of young galaxies, yet efforts have been hindered by observational limitations in both sensitivity and spatial resolution.

Author notes These authors contributed equally: B. E. Robertson, S. Tacchella. Authors and Affiliations Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA, USA B. E. Robertson & K. A. Suess Kavli Institute for Cosmology, University of Cambridge, Cambridge, UK S. Tacchella, M. Curti, F. D’Eugenio, T. J. Looser, R. Maiolino, H. Übler, J. Witstok & L. Sandles Cavendish Laboratory, University of Cambridge, Cambridge, UK S. Tacchella, M. Curti, F. D’Eugenio, T. J. Looser, R. Maiolino, H.