English

Connecting Primordial Star Forming Regions and Second Generation Star Formation in the Phoenix Simulations

Astrophysics of Galaxies 2022-06-22 v1

Abstract

We introduce the {\em Phoenix Simulations}, a suite of highly resolved cosmological simulations featuring hydrodynamics, primordial gas chemistry, Population III and II star formation and feedback, UV radiative transfer, and saved outputs with Δt\Delta t=200 kyr. The suite samples 73,523 distinct primordial star formation events within \npiii distinct regions, forming \ngii second-generation enriched star clusters by z12z \geq 12 within a cumulative 156.25 Mpc3^3 volume. The regions that lead to enriched star formation contain up to 167167 primordial stars, with 78.7 \% of regions having experienced multiple types of primordial supernovae. The extent of a primordial region, measured by its metal-rich surrounding cloud, is highly variable: the average region has radius 3\sim 3 kpc, with 95 \% confidence limit on the distribution of measured radii is 57\sim 5-7 kpc. For continuing star formation, we find that the metallicity distribution of second generation stars is similar to that of subsequent Population II star formation, with both distributions spanning hyper metal-deficient ([Z/H]7\sim-7) to super-solar ([Z/H]0.8\sim0.8). We find that the metallicity of second generation stars has no strong dependence on the configuration of progenitor supernovae, with the mean metallicity of second-generation stars having 1.73<-1.73 < [Z/H]<2.15<-2.15. Finally, we create an interpretable regression model to predict the radius of metal-rich influence of \piii star systems within the first 7-18 Myr after the first light. The model predicts the radius with R20.4R_2 \gtrsim 0.4 and mean squared error 0.06\leq 0.06. The probability distribution function of predicted radii compares well to that of observed radii with Jensen-Shannon distance 0.2\lesssim 0.2 for all modelled times.

Keywords

Cite

@article{arxiv.2111.10651,
  title  = {Connecting Primordial Star Forming Regions and Second Generation Star Formation in the Phoenix Simulations},
  author = {Azton I. Wells and Michael L. Norman},
  journal= {arXiv preprint arXiv:2111.10651},
  year   = {2022}
}