The Epoch of Reionization in Warm Dark Matter Scenarios

TL;DR

This study examines how different warm dark matter cosmologies influence the epoch of reionization, using semi-analytic models to compare predictions with observations and identify escape fraction limits.

Contribution

It introduces a semi-analytic approach to model reionization in warm dark matter scenarios, analyzing the impact of galaxy formation and escape fractions on ionization history.

Findings

Reionization completes at z<6.7 for certain escape fractions.

Warm dark matter models affect the UV luminosity function.

Predictions align with observational constraints.

Abstract

In this paper we investigate how the Reionization process is affected by early galaxy formation in different cosmological scenarios. We use a semi-analytic model with suppressed initial power spectra to obtain the UV Luminosity Function in thermal Warm Dark Matter and sterile neutrino cosmologies. We retrace the ionization history of intergalactic medium with hot stellar emission only, exploiting fixed and variable photons escape fraction models ($f_{esc}$). For each cosmology, we find an upper limit to fixed $f_{esc}$, which guarantees the completion of the process at $z<6.7$. The analysis is tested with two limit hypothesis on high-z ionized hydrogen volume fraction, comparing our predictions with observational results.