Star formation and chemical enrichment in Protoclusters
Keita Fukushima, Kentaro Nagamine, Ikkoh Shimizu- Space and Planetary Science
- Astronomy and Astrophysics
Abstract
We examine star formation and chemical enrichment in protoclusters (PCs) using cosmological zoom-in hydrodynamic simulations. We find that the total star formation rate (SFR) in all PC (>1014.4 h−1 M⊙) reaches >104 M⊙yr−1 at z = 3, equivalent to the observed PCs. The SFR in the Core region accounts for about 30 % of the total star formation in the PC at z ≳ 1, suggesting the importance of the outer regions to reveal the evolution of galaxy clusters. We find that the total SFR of PC is dominated by galaxies with stellar masses 1010 ≤ (M⋆/M⊙) ≤ 1011, while more massive galaxies dominate the SFR in the Core. For the chemical abundance evolution, we find that the higher-density region has a higher metallicity and faster evolution. We show that the [O/Fe] vs. [Fe/H] relation turns down in the Core at z = 3.4 due to the enrichment of Fe by Type Ia supernovae. We find no environmental effects for the mass–metallicity relations (MZR) or log (N/O) vs. 12 + log (O/H) for galaxies. We find that the chemical enrichment in galaxy clusters proceeds faster in the high-redshift universe (z > 1). Our work will benefit future tomographic observations, particularly using PCs as unique probes of accelerated structure formation and evolution in high-density regions of the universe.