AEOS: Transport of Metals from Minihalos following Population III Stellar Feedback

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, A eos . 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 mass M _dm ≲ 10 ^7 M _⊙ , regardless of the number of SNe. This prevents self-enrichment and results in a nonmonotonic increase in metallicity at early times. Most minihalos ( M _dm ≳ 10 ^5 M _⊙ ) do not retain significant fractions of the yields produced within their virial radii until they have grown to halo masses of M _dm ≳ 10 ^7 M _⊙ . 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 redshift z = 14.3), enrichment is dominated by core-collapse supernovae for all elements, but with a significant contribution from asymptotic giant branch winds to the s -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 A eos in later epochs to trace the evolution of enrichment during the complete transition from Population III to Population II stars.

Keywords

• Population III stars
• Hydrodynamical simulations
• Chemical enrichment
• Galaxy chemical evolution
• Dwarf galaxies
• Stellar feedback