The emergence of globular clusters and globular-cluster-like dwarfs

Ethan Taylor; Justin I. Read; Matthew D. A. Orkney; Stacy Y. Kim; Andrew Pontzen; Oscar Agertz; Martin Rey; Eric P. Andersson; Michelle Collins; Robert M Yates

doi:10.1038/s41586-025-09494-x

The emergence of globular clusters and globular-cluster-like dwarfs

Ethan Taylor, Justin I. Read, Matthew D. A. Orkney, Stacy Y. Kim, Andrew Pontzen, Oscar Agertz, Martin Rey, Eric P. Andersson, Michelle Collins, Robert M Yates

Research output: Contribution to journal › Article › peer-review

2 Citations (SciVal)

Abstract

Globular clusters (GCs) are among the oldest and densest stellar systems in the Universe, yet how they form remains a mystery1. Here we present a suite of cosmological simulations in which both dark-matter-free GCs and dark-matter-rich dwarf galaxies naturally emerge in the Standard Cosmology. We show that these objects inhabit distinct locations in the size–luminosity plane and that they have similar ages, age spread, metallicity and metallicity spread to globulars and dwarfs in the nearby Universe. About half of our simulated globulars form by means of regular star formation near the centres of their host dwarf, with the rest forming further out, triggered by mergers. The latter are more tidally isolated and more likely to survive to the present day. Finally, our simulations predict the existence of a new class of object that we call ‘globular-cluster-like dwarfs’ (GCDs). These form from a single, self-quenching, star-formation event in low-mass dark-matter halos at high redshift and have observational properties intermediate between globulars and dwarfs. We identify several dwarfs in our Galaxy, such as Reticulum II (refs. 2,3,4), that could be in this new class. If so, they promise unprecedented constraints on dark-matter models and new sites to search for metal-free stars.

Original language	English
Pages (from-to)	327-331
Number of pages	5
Journal	Nature
Volume	645
Early online date	10 Sept 2025
DOIs	https://doi.org/10.1038/s41586-025-09494-x
Publication status	Published - 11 Sept 2025

Data Availability Statement

Raw simulation data can be made available from the authors on request, including software to load in and analyse the data. Files to regenerate the initial conditions of the simulations used in the paper have been uploaded at https://zenodo.org/records/16536387 (ref. 158). The DOI associated with this dataset is https://doi.org/10.5281/zenodo.16536387.

Funding

E.D.T. acknowledges support from the UKRI Science and Technology Facilities Council (STFC; grants ST/V50712X/1 and ST/Y002865/1). J.I.R. and M.L.M.C. acknowledge support from STFC grants ST/Y002865/1 and ST/Y002857/1. M.D.A.O acknowledges funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 852839). O.A. acknowledges support from the Knut and Alice Wallenberg Foundation, the Swedish Research Council (grant 2019-04659) and the Swedish National Space Agency (SNSA Dnr 2023-00164). E.P.A. acknowledges support from US NSF grants AST18-15461 and AST23-07950 and NASA ATP grant 80NSSC24K0935. A.P. received support from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 818085 GMGalaxies. This work used both the DiRAC Data Intensive service (DIaL2) hosted and managed by the University of Leicester Research Computing Service and the DiRAC@Durham (cosma6) facility hosted and managed by the Institute for Computational Cosmology on behalf of the STFC DiRAC HPC Facility ( www.dirac.ac.uk ). The equipment was financed by BEIS capital funding through STFC capital grants ST/P002293/1, ST/R002371/1 and ST/S002502/1, Durham University and STFC operations grant ST/R000832/1. DiRAC is part of the National e-Infrastructure. We wish to thank A. Fattahi for helpful comments on an early draft of this work. E.D.T. acknowledges support from the UKRI Science and Technology Facilities Council (STFC; grants ST/V50712X/1 and ST/Y002865/1). J.I.R. and M.L.M.C. acknowledge support from STFC grants ST/Y002865/1 and ST/Y002857/1. M.D.A.O acknowledges funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 852839). O.A. acknowledges support from the Knut and Alice Wallenberg Foundation, the Swedish Research Council (grant 2019-04659) and the Swedish National Space Agency (SNSA Dnr 2023-00164). E.P.A. acknowledges support from US NSF grants AST18-15461 and AST23-07950 and NASA ATP grant 80NSSC24K0935. A.P. received support from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 818085 GMGalaxies. This work used both the DiRAC Data Intensive service (DIaL2) hosted and managed by the University of Leicester Research Computing Service and the DiRAC@Durham (cosma6) facility hosted and managed by the Institute for Computational Cosmology on behalf of the STFC DiRAC HPC Facility (www.dirac.ac.uk). The equipment was financed by BEIS capital funding through STFC capital grants ST/P002293/1, ST/R002371/1 and ST/S002502/1, Durham University and STFC operations grant ST/R000832/1. DiRAC is part of the National e-Infrastructure. We wish to thank A. Fattahi for helpful comments on an early draft of this work.

Funders	Funder number
Knut och Alice Wallenbergs Stiftelse
University of Leicester
European Research Council
National Aeronautics and Space Administration	80NSSC24K0935
Vetenskapsrådet	2019-04659
Department for Business, Energy & Industrial Strategy	ST/R002371/1, ST/S002502/1, ST/P002293/1
Swedish National Space Agency	Dnr 2023-00164
Durham University	ST/R000832/1
National Science Foundation	AST23-07950, AST18-15461
Horizon 2020 Framework Programme	852839, 818085 GMGalaxies
Science and Technology Facilities Council	ST/Y002857/1, ST/V50712X/1, ST/Y002865/1

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10.1038/s41586-025-09494-xLicence: CC BY

Cite this

@article{7516eb0e22e64c9a8298de1ecdfd979c,

title = "The emergence of globular clusters and globular-cluster-like dwarfs",

abstract = "Globular clusters (GCs) are among the oldest and densest stellar systems in the Universe, yet how they form remains a mystery1. Here we present a suite of cosmological simulations in which both dark-matter-free GCs and dark-matter-rich dwarf galaxies naturally emerge in the Standard Cosmology. We show that these objects inhabit distinct locations in the size–luminosity plane and that they have similar ages, age spread, metallicity and metallicity spread to globulars and dwarfs in the nearby Universe. About half of our simulated globulars form by means of regular star formation near the centres of their host dwarf, with the rest forming further out, triggered by mergers. The latter are more tidally isolated and more likely to survive to the present day. Finally, our simulations predict the existence of a new class of object that we call {\textquoteleft}globular-cluster-like dwarfs{\textquoteright} (GCDs). These form from a single, self-quenching, star-formation event in low-mass dark-matter halos at high redshift and have observational properties intermediate between globulars and dwarfs. We identify several dwarfs in our Galaxy, such as Reticulum II (refs. 2,3,4), that could be in this new class. If so, they promise unprecedented constraints on dark-matter models and new sites to search for metal-free stars.",

author = "Ethan Taylor and Read, \{Justin I.\} and Orkney, \{Matthew D. A.\} and Kim, \{Stacy Y.\} and Andrew Pontzen and Oscar Agertz and Martin Rey and Andersson, \{Eric P.\} and Michelle Collins and Yates, \{Robert M\}",

year = "2025",

month = sep,

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doi = "10.1038/s41586-025-09494-x",

language = "English",

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pages = "327--331",

journal = "Nature",

issn = "0028-0836",

publisher = "Nature Research",

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T1 - The emergence of globular clusters and globular-cluster-like dwarfs

AU - Taylor, Ethan

AU - Read, Justin I.

AU - Orkney, Matthew D. A.

AU - Kim, Stacy Y.

AU - Pontzen, Andrew

AU - Agertz, Oscar

AU - Rey, Martin

AU - Andersson, Eric P.

AU - Collins, Michelle

AU - Yates, Robert M

PY - 2025/9/11

Y1 - 2025/9/11

N2 - Globular clusters (GCs) are among the oldest and densest stellar systems in the Universe, yet how they form remains a mystery1. Here we present a suite of cosmological simulations in which both dark-matter-free GCs and dark-matter-rich dwarf galaxies naturally emerge in the Standard Cosmology. We show that these objects inhabit distinct locations in the size–luminosity plane and that they have similar ages, age spread, metallicity and metallicity spread to globulars and dwarfs in the nearby Universe. About half of our simulated globulars form by means of regular star formation near the centres of their host dwarf, with the rest forming further out, triggered by mergers. The latter are more tidally isolated and more likely to survive to the present day. Finally, our simulations predict the existence of a new class of object that we call ‘globular-cluster-like dwarfs’ (GCDs). These form from a single, self-quenching, star-formation event in low-mass dark-matter halos at high redshift and have observational properties intermediate between globulars and dwarfs. We identify several dwarfs in our Galaxy, such as Reticulum II (refs. 2,3,4), that could be in this new class. If so, they promise unprecedented constraints on dark-matter models and new sites to search for metal-free stars.

AB - Globular clusters (GCs) are among the oldest and densest stellar systems in the Universe, yet how they form remains a mystery1. Here we present a suite of cosmological simulations in which both dark-matter-free GCs and dark-matter-rich dwarf galaxies naturally emerge in the Standard Cosmology. We show that these objects inhabit distinct locations in the size–luminosity plane and that they have similar ages, age spread, metallicity and metallicity spread to globulars and dwarfs in the nearby Universe. About half of our simulated globulars form by means of regular star formation near the centres of their host dwarf, with the rest forming further out, triggered by mergers. The latter are more tidally isolated and more likely to survive to the present day. Finally, our simulations predict the existence of a new class of object that we call ‘globular-cluster-like dwarfs’ (GCDs). These form from a single, self-quenching, star-formation event in low-mass dark-matter halos at high redshift and have observational properties intermediate between globulars and dwarfs. We identify several dwarfs in our Galaxy, such as Reticulum II (refs. 2,3,4), that could be in this new class. If so, they promise unprecedented constraints on dark-matter models and new sites to search for metal-free stars.

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The emergence of globular clusters and globular-cluster-like dwarfs

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Engineering Dwarf Galaxy at the Edge of galaxy formation

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The emergence of globular clusters and globular-cluster-like dwarfs

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Data Availability Statement

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Engineering Dwarf Galaxy at the Edge of galaxy formation

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