Abstract

The Epoch of Reionization is a major phase transition in the universe's history, but the nature of the ionizing sources and the physical processes involved are still largely unconstrained. This talk will present the results of recent works trying to shed light on these questions. During the first part, I will present the results of recent studies focusing on HI absorption lines and Lyman profiles observed in low-redshift Lyman continuum emitters. These works highlighted that the ISM porosity and dust attenuation are crucial ingredients regulating the escape of Lyman-alpha and ionizing photons in these galaxies.

In the second part of this talk, I will talk about how future 21-cm tomographic observations obtained with the Square Kilometer Array will be crucial to constrain the properties of the ionizing sources. In particular, I will show how the morphological properties of the ionized regions trace the astrophysics of reionization and can be incorporated in a Bayesian inference framework to disentangle multiple reionization scenarios.