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Abstract We investigate how stellar feedback from the first stars (Population III) distributes metals through the interstellar and intergalactic medium using the star-by-star cosmological hydrodynamics simulation, Aeos. We find that energy injected from the supernovae (SNe) of the first stars is enough to expel a majority of gas and injected metals beyond the virial radius of halos with massMdm ≲ 107M⊙, regardless of the number of SNe. This prevents self-enrichment and results in a nonmonotonic increase in metallicity at early times. Most minihalos (Mdm ≳ 105M⊙) do not retain significant fractions of the yields produced within their virial radii until they have grown to halo masses ofMdm ≳ 107M⊙. The loss of metals to regions well beyond the virial radius delays the onset of enriched star formation and extends the period that Population III star formation can persist. We also explore the contributions of different nucleosynthetic channels to 10 individual elements. On the timescale of the simulation (lowest redshiftz= 14.3), enrichment is dominated by core-collapse supernovae for all elements, but with a significant contribution from asymptotic giant branch winds to thes-process elements, which are normally thought to only be important at late times. In this work, we establish important mechanisms for early chemical enrichment, which allows us to apply Aeosin later epochs to trace the evolution of enrichment during the complete transition from Population III to Population II stars.
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This content will become publicly available on February 3, 2026
AEOS: Star-by-star Cosmological Simulations of Early Chemical Enrichment and Galaxy Formation
Abstract The Aeosproject introduces a series of high-resolution cosmological simulations that model star-by-star chemical enrichment and galaxy formation in the early Universe, achieving 1 pc resolution. These simulations capture the complexities of galaxy evolution within the first ~300 Myr by modeling individual stars and their feedback processes. By incorporating chemical yields from individual stars, Aeosgenerates galaxies with diverse stellar chemical abundances, linking them to hierarchical galaxy formation and early nucleosynthetic events. These simulations underscore the importance of chemical abundance patterns in ancient stars as vital probes of early nucleosynthesis, star formation histories, and galaxy formation. We examine the metallicity floors of various elements resulting from Population III enrichment, providing best-fit values for eight different metals (e.g., [O/H] = −4.0) to guide simulations without Population III models. Additionally, we identify galaxies that begin star formation with Population II after external enrichment and investigate the frequency of carbon-enhanced metal-poor stars at varying metallicities. The Aeossimulations offer detailed insights into the relationship between star formation, feedback, and chemical enrichment. Future work will extend these simulations to later epochs to interpret the diverse stellar populations of the Milky Way and its satellites.
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- PAR ID:
- 10582971
- Publisher / Repository:
- American Astronomical Society
- Date Published:
- Journal Name:
- The Astrophysical Journal
- Volume:
- 980
- Issue:
- 1
- ISSN:
- 0004-637X
- Page Range / eLocation ID:
- 41
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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