@article{20255,
  abstract     = {With stunning clarity, the JWST has revealed the Universe’s first billion years. The scientific community is analysing a wealth of JWST imaging and spectroscopic data from that era, and is in the process of rewriting the astronomy textbooks. Here, as a result of the 2024 ISSI Breakthrough Workshop, we provide a snapshot of the great progress made towards understanding the initial chapters of our cosmic history 1.5 years into the JWST science mission. We present the current census of early galaxies, their luminosities, appearance, chemical composition, masses and formation histories as revealed by JWST. We relate the discovery of massive black holes in early galaxies and discuss their demographics and implications for their formations and growth. We conclude by describing the potential sources of reionization and our current understanding of how the Universe became fully ionized. Throughout the Perspective, we highlight discoveries and breakthroughs, topics and issues that are not yet understood, and questions that will be addressed in the coming years, as JWST continues its revolutionary observations of the early Universe.},
  author       = {Adamo, Angela and Atek, Hakim and Bagley, Micaela B. and Bañados, Eduardo and Barrow, Kirk S.S. and Berg, Danielle A. and Bezanson, Rachel and Bradač, Maruša and Brammer, Gabriel and Carnall, Adam C. and Chisholm, John and Coe, Dan and Dayal, Pratika and Eisenstein, Daniel J. and Eldridge, Jan J. and Ferrara, Andrea and Fujimoto, Seiji and Graaff, Anna De and Habouzit, Melanie and Hutchison, Taylor A. and Kartaltepe, Jeyhan S. and Kassin, Susan A. and Kriek, Mariska and Labbé, Ivo and Maiolino, Roberto and Marques-Chaves, Rui and Maseda, Michael V. and Mason, Charlotte and Matthee, Jorryt J and Mcquinn, Kristen B.W. and Meynet, Georges and Naidu, Rohan P. and Oesch, Pascal A. and Pentericci, Laura and Pérez-González, Pablo G. and Rigby, Jane R. and Roberts-Borsani, Guido and Schaerer, Daniel and Shapley, Alice E. and Stark, Daniel P. and Stiavelli, Massimo and Strom, Allison L. and Vanzella, Eros and Wang, Feige and Wilkins, Stephen M. and Williams, Christina C. and Willott, Chris J. and Wylezalek, Dominika and Nota, Antonella},
  issn         = {2397-3366},
  journal      = {Nature Astronomy},
  number       = {8},
  pages        = {1134--1147},
  publisher    = {Springer Nature},
  title        = {{The first billion years according to JWST}},
  doi          = {10.1038/s41550-025-02624-5},
  volume       = {9},
  year         = {2025},
}