Work

Exploring the effect of different cosmologies on the Epoch of Reionization 21-cm signal with polar

Year: 2025

Type: article

Abstract: ABSTRACT A detection of the 21-cm signal power spectrum from the Epoch of Reionization is imminent, thanks to consistent advancements from telescopes such as LOFAR, MWA, and HERA, along with the development of SKA. In light of this progress, it is crucial to expand the parameter space of simulations used to infer astrophysical properties from this signal. In this work, we explore the role of cosmological parameters such as the Hubble constant $H_0$ and the matter clustering amplitude $\sigma _8$, whose values as provided by measurements at different redshifts are in tension. We run N-body simulations using gadget-4, and post-process them with the reionization simulation code polar, that uses L-Galaxies to include galaxy formation and evolution properties and grizzly to execute 1D radiative transfer of ionizing photons in the intergalactic medium (IGM). We compare our results with the latest James Webb Space Telescope (JWST) observations and explore which astrophysical properties for different cosmologies are necessary to match the observed UV luminosity functions at redshifts $z = 10$ and 9. Additionally, we explore the impact of these parameters on the observed 21-cm signal power spectrum upper limits, focusing on the redshifts within the range of LOFAR 21-cm signal observations ($z \approx 8.5\!-\!10$). Despite differences in cosmological and astrophysical parameters, our models cannot be ruled out by the current upper limits. This suggests the need for broader physical parameter spaces for inference modeling to account for all models that agree with observations. However, we also propose stronger constraining power by using a combination of galactic and IGM observables.

Source: Monthly Notices of the Royal Astronomical Society

DOI: 10.1093/mnras/staf1412