The Inhomogeneous Background of $H2$ Dissociating Radiation During Cosmic Reionization

The first, self‐consistent calculations of the cosmological $H2$ dissociating UV background produced during the epoch of reionization by the sources of reionization are presented. Large‐scale radiative transfer simulations of reionization trace the impact of all the ionizing starlight on the IGM from all sources in our simulation volume down to dwarf galaxies of mass $∼108 M⊙,$ identified by very high‐resolution N‐body simulations, including the self‐regulating effect of IGM photoheating on dwarf galaxy formation. The UV continuum emitted below 13.6 eV by each source is then transferred through the same IGM, attenuated by atomic H Lyman series resonance lines, to predict the evolution of the inhomogeneous background in the Lyman‐Werner band of $H2$ between 11 and 13.6 eV.