The late reionization of filaments

摘要: We study the topology of reionization using accurate three-dimensional radiative transfer calculations post-processed on outputs from cosmological hydrodynamic simulations. In our simulations, begins in overdense regions and then 'leaks' directly into voids, with filaments reionizing last owing to their combination a high recombination rate low emissivity. This result depends uniquely biased emissivity field predicted by prescriptions for star formation feedback, which have previously been shown account wide array measurements post-reionization Universe. It is qualitatively robust choice simulation volume, ionizing escape fraction spatial resolution (in fact, it grows stronger at higher resolution) even though exact overlap redshift sensitive each these. However, weakens slightly as increased reduced density contrast redshift. also explore whether results are commonly employed approximations such optically thin Eddington tensors or substantially altering speed light. Such do not change reionization. they can systematically shift up Δz ∼ 0.5, indicating that essential computing Our model cannot simultaneously reproduce observed optical depth Thomson scattering ionization per hydrogen atom z = 6, could owe numerical effects and/or missing early sources ionization.