MEGATRON: how the first stars can create an iron metallicity plateau in the smallest dwarf galaxies
Year: 2026
Type: article
Abstract: We study the stellar mass-iron metallicity relation of dwarf galaxies in the new high-resolution MEGATRON cosmological radiation-hydrodynamics simulations. These simulations model galaxy formation up to z ≈ 8 in a region that will collapse into a Milky-Way-like galaxy at z = 0 , while self-consistently tracking Population III and II (Pop.~III, Pop.~II) star formation, feedback and chemical enrichment. MEGATRON dwarf galaxies are in excellent agreement with the observed stellar mass-metallicity relation at z = 0 , including an over-abundance of dwarfs along a flat plateau in metallicity () at low stellar masses (). We tie this feature to the chemical enrichment of dwarf galaxies by Pop. III pair-instability supernova (PISN) explosions. The strong Lyman-Werner background (LW) from the protogalaxy ensures that PISNe occur in haloes massive enough () to retain their ejecta. We also predict a tail of ≈ 20 % of iron-deficient () dwarf galaxies. We show that both plateau and tail (i) are robust to large variations in Pop.~II feedback assumptions, and (ii) survive in bound satellites surrounding the central galaxy at z = 0 .
Source: The Open Journal of Astrophysics
DOI: 10.33232/001c.169605
Authors: Martin Rey, Harley Katz, Corentin Cadiou, Mahsa Sanati, Oscar Agertz, Jeremy Blaizot, Alex J. Cameron, Nicholas Choustikov, Julien Devriendt, Uliana Hauk, Alexander P. Ji, Gareth C. Jones, Taysun Kimm, Isaac Laseter, Sergio Martin-Alvarez, Kosei Matsumoto, Autumn Pearce, Yves Revaz, Francisco Rodriguez Montero, Joki Rosdahl, Aayush Saxena, Adrianne Slyz, Richard Stiskalek, Anatole Storck, Oscar Veenema, Wonjae Yee
Institutions: Skåne University Hospital, University of Oxford, Institut d'Astrophysique de Paris, Lund University, Centre de Recherche Astrophysique de Lyon, University of Aberdeen, Yonsei University, University of Wisconsin–Madison, University of Cambridge, École Polytechnique Fédérale de Lausanne, École Normale Supérieure - PSL
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
Funders: National Science Foundation, National Aeronautics and Space Administration, University of Chicago, Dell EMC, UK Research and Innovation, Liam M. Kinne Foundation, University of Leicester, University of Oxford, European Commission, Durham University, National Research Foundation, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Swedish National Space Agency, Yonsei University, Fonds Wetenschappelijk Onderzoek, National Research Foundation of Korea, Knut och Alice Wallenbergs Stiftelse, Vetenskapsrådet, Vlaamse regering, Engineering and Physical Sciences Research Council, Science and Technology Facilities Council
Awards: G1251748267, G1374990094, G1468651527, G1571591014, G1592084823, A diagnosis of galaxy evolution with molecular gas, G1744961100, DiRAC-2.5 - the pathway to DiRAC Phase 3, G2126713887, G2144673021, G2309215924, G2368581224, G23881487, G2768788806, G2820069179, G2843074508, The DiRAC 2.5x Facility, G3260510625, G3363198467, G360800292, G361763971, G3722612171, G3736842604, G4251892262, G4272648177, G4288509881, ALICE and ATLAS, G4436073038, G4498713678, G458729750, G4862659593, G4915654406, G5016509646, G5275711260, G5385953647, G5480708011, G5497405240, G5550154303, G581313191, G5832396093, G6285136898, G6398031381, DiRAC-2.5 DC - Operations 2017-2020, G6480477771, G682590366, G6860730371, Cambridge Service for Data Driven Discovery (CSD3) - A National Data Intensive Science Cloud for Converged Simulation, AI & Analytics, G7028966183, G7123058552, G7495247241, DiRAC2: 100 Tflop/s HPC cluster procurement, G7678768968, G7724874892, G7935691682, DiRAC: Memory Intensive 2.5y, A new way of understanding the origins of the Milky Way galaxy, Connecting galaxy formation and Cosmic Reionization, G825883484, G8580302071, ARRAKIHS - Analysis of Resolved Remnants of Accreted galaxies as a Key Instrument for Halo Surveys, G8931419319, G8962111125, DiRAC 2.5 Operations 2017-2020, DiRAC: Memory Intensive 2.5x
OpenAlex ID: W4414974059