The role of Pop III stars and early black holes in the 21-cm signal from Cosmic Dawn

Abstract

Modeling the 21-cm global signal from the Cosmic Dawn is challenging due to the many poorly constrained physical processes that come into play. We address this problem using the semi-analytical code ‘Cosmic Archaeology Tool’ (CAT). CAT follows the evolution of dark matter haloes tracking their merger history and provides an ab initio description of their baryonic evolution, starting from the formation of the first (Pop III) stars and black holes (BHs) in mini-haloes at z > 20. The model is anchored to observations of galaxies and AGN at z < 6 and predicts a reionization history consistent with constraints. In this work, we compute the evolution of the mean global 21-cm signal between 4 ≤ z ≤..