Cosmic Dawn

Cosmic Dawn II (CoDa II) is a fully coupled radiation-hydrodynamics simulation of cosmic reionization and galaxy formation and their mutual impact, to redshift z < 6. With 4096^3 particles and cells in a 94 Mpc box, it is large enough to model global reionization and its feedback on galaxy formation while resolving all haloes above 10^8 solar masses.

The progenitors of several major Local Universe objects were traced back from z = 0 to z = 6. They are labelled on this figure to allow to gauge their reionization history and radiative influence region during the epoch of reionization. The map shows local maxima of the reionisation redshift, which are ‘islands’ of early reionization surrounded by a ‘sea’ of late reionization. Such regions like Milky Way and Andromeda (M31) are internally reionized, in an inside-out pattern. The Virgo cluster’s progenitor, is also separated and therefore not responsible for the reionization of the Local Group. The projet is described in Ocvirk et al. 2020 and a serie of follow up papers (see publications).