A massive galaxy that formed its stars at z ≈ 11

Karl Glazebrook; Themiya Nanayakkara; Corentin Schreiber; Claudia Lagos; Lalitwadee Kawinwanichakij; Colin Jacobs; Harry Chittenden; Gabriel Brammer; Glenn G Kacprzak; Ivo Labbe; Danilo Marchesini; Z Cemile Marsan; Pascal A Oesch; Casey Papovich; Rhea-Silvia Remus; Kim-Vy H Tran; James Esdaile; Angel Chandro-Gomez

doi:10.1038/s41586-024-07191-9

A massive galaxy that formed its stars at z ≈ 11

Nature. 2024 Apr;628(8007):277-281. doi: 10.1038/s41586-024-07191-9. Epub 2024 Feb 14.

Authors

Karl Glazebrook¹, Themiya Nanayakkara², Corentin Schreiber³, Claudia Lagos^{4

5

6}, Lalitwadee Kawinwanichakij², Colin Jacobs², Harry Chittenden², Gabriel Brammer⁴, Glenn G Kacprzak², Ivo Labbe², Danilo Marchesini⁷, Z Cemile Marsan⁸, Pascal A Oesch^{4

9}, Casey Papovich¹⁰, Rhea-Silvia Remus¹¹, Kim-Vy H Tran^{5

12

13}, James Esdaile², Angel Chandro-Gomez⁶

Affiliations

¹ Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria, Australia. kglazebrook@swin.edu.au.
² Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria, Australia.
³ IBEX Innovations, Stockton-on-Tees, UK.
⁴ Cosmic DAWN Center, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
⁵ ARC Centre for Excellence in All-Sky Astrophysics in 3D, Canberra, Australian Capital Territory, Australia.
⁶ International Centre for Radio Astronomy Research, University of Western Australia, Crawley, Western Australia, Australia.
⁷ Physics and Astronomy Department, Tufts University, Medford, MA, USA.
⁸ Department of Physics and Astronomy, York University, Toronto, Ontario, Canada.
⁹ Department of Astronomy, University of Geneva, Versoix, Switzerland.
¹⁰ Department of Physics and Astronomy, and George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, TX, USA.
¹¹ Universitäts-Sternwarte, Fakultät für Physik, Ludwig-Maximilians-Universität München, Munich, Germany.
¹² School of Physics, University of New South Wales, Kensington, New South Wales, Australia.
¹³ Center for Astrophysics, Harvard & Smithsonian, Cambridge, MA, USA.

PMID: 38354832
DOI: 10.1038/s41586-024-07191-9

Abstract

The formation of galaxies by gradual hierarchical co-assembly of baryons and cold dark matter halos is a fundamental paradigm underpinning modern astrophysics^1,2 and predicts a strong decline in the number of massive galaxies at early cosmic times^3-5. Extremely massive quiescent galaxies (stellar masses of more than 10¹¹ M_⊙) have now been observed as early as 1-2 billion years after the Big Bang^6-13. These galaxies are extremely constraining on theoretical models, as they had formed 300-500 Myr earlier, and only some models can form massive galaxies this early^12,14. Here we report on the spectroscopic observations with the JWST of a massive quiescent galaxy ZF-UDS-7329 at redshift 3.205 ± 0.005. It has eluded deep ground-based spectroscopy⁸, it is significantly redder than is typical and its spectrum reveals features typical of much older stellar populations. Detailed modelling shows that its stellar population formed around 1.5 billion years earlier in time (z ≈ 11) at an epoch when dark matter halos of sufficient hosting mass had not yet assembled in the standard scenario^4,5. This observation may indicate the presence of undetected populations of early galaxies and the possibility of significant gaps in our understanding of early stellar populations, galaxy formation and the nature of dark matter.