#import "helpers.typ": *

We present #beorn, a semi-numerical simulation suite that uses a simplified description of radiation sources to efficiently generate maps of the cosmic dawn and the epoch of reionization.
In its original formulation, the framework assumed exponential halo growth with a fixed accretion rate. We show how this assumption introduces systematic inaccuracies in the predicted observables of reionization. In this work, we implement a more realistic description of halo mass growth that follows the mass accretion history of individual halos.
We achieve this consistent treatment of halo growth by incorporating individual accretion histories extracted from the merger trees provided by the #thesan simulations.
This required an extensive refactoring of the #beorn code base, redesigning the computation of the radiative source properties to accommodate variable growth while ensuring scalability and computational efficiency.
We describe these modifications in detail and validate the improved suite against the original implementation.
We demonstrate that the refined treatment alters the timing and morphology properties of the reionization. Finally, we discuss how this new version of #beorn provides a more robust platform for exploring reionization scenarios, and we outline planned extensions and applications.
