Detectability of 21-cm Power Spectra from the Epoch of Reionization using Modern Radio Telescopes

Abstract

One of the unsolved questions in astrophysics and cosmology is the development of a robust physical model to explain the thermal history of the intergalactic medium during the epoch of reionization. Various astrophysical models have been proposed, but current models remain only partially constrained by available observations. To clarify this ambiguity, hydrodynamical, semi-numerical, and N-body simulations can help solve this issue. One notable simulation from the epoch of reionization is the 21SSD simulations, which provide high-resolution results for the global 21-cm brightness temperature and the 21-cm power spectrum during the epoch of reionization. The simulation includes 45 models spanning three key astrophysical parameters of X-ray emissivity, Lyman-band emissivity, and the X-ray hard-to-soft emissivity ratio. Distinct values of these parameters result in different models of this simulation. In this work, four active radio observatories, including HERA, MWA, GMRT, and LOFAR have been considered to investigate the sensitivity and thermal noise of the 21-cm power spectrum. Each observatory has a particular sensitivity based on its instrumental characteristics, which helps assess which models lie above the forecast sensitivity thresholds of current instruments.