Two-dimensional Topology of Cosmological Reionization

TL;DR

This paper analyzes the two-dimensional topology of 21-cm brightness temperature during reionization using simulations and models, showing its potential to distinguish different reionization scenarios and constrain models.

Contribution

It introduces a topology analysis method for 21-cm data that effectively differentiates reionization models and can be applied to future observations.

Findings

Genus curves vary significantly with ionized fraction.

Topology analysis distinguishes different reionization scenarios.

Method is applicable to future SKA observations.

Abstract

We study the two-dimensional topology of the 21-cm differential brightness temperature for two hydrodynamic radiative transfer simulations and two semi-numerical models. In each model, we calculate the two dimensional genus curve for the early, middle and late epochs of reionization. It is found that the genus curve depends strongly on the ionized fraction of hydrogen in each model. The genus curves are significantly different for different reionization scenarios even when the ionized faction is the same. We find that the two-dimensional topology analysis method is a useful tool to constrain the reionization models. Our method can be applied to the future observations such as those of the Square Kilometer Array.