SIMBAD references

Using three-dimensional cosmological simulations, we study the assembly process of one of the first galaxies, with a total mass of ∼10⁸ M_☉, collapsing at z =~ 10. Our main goal is to trace the transport of the heavy chemical elements produced and dispersed by a pair-instability supernova exploding in one of the minihalo progenitors. To this extent, we incorporate an efficient algorithm into our smoothed particle hydrodynamics code that approximately models turbulent mixing as a diffusion process. We study this mixing with and without the radiative feedback from Population III (Pop III) stars that subsequently form in neighboring minihalos. Our simulations allow us to constrain the initial conditions for second-generation star formation, within the first galaxy itself, and inside of minihalos that virialize after the supernova explosion. We find that most minihalos remain unscathed by ionizing radiation or the supernova remnant, while some are substantially photoheated and enriched to supercritical levels, likely resulting in the formation of low-mass Pop III or even Population II (Pop II) stars. At the center of the newly formed galaxy, ∼10⁵ M_☉ of cold, dense gas uniformly enriched to ∼10^–3 Z_☉ is in a state of collapse, suggesting that a cluster of Pop II stars will form. The first galaxies, as may be detected by the James Webb Space Telescope, would therefore already contain stellar populations familiar from lower redshifts.