Estimating the Feasibility of 21cm-Ly$\alpha$ Synergies using the Hydrogen Epoch of Reionization Array

Understand

Cross-correlating 21cm and Ly$\alpha$ intensity maps of the Epoch of Reionization (EoR) promises to be a powerful tool for exploring the properties of the first galaxies.

• Next-generation intensity mapping experiments such as the Hydrogen Epoch of Reionization Array (HERA) and SPHEREx will individually probe reionization through the power spectra of the 21cm and Ly$\alpha$ lines respectively, but will be limited by bright foregrounds and instrumental systematics.
• Cross-correlating these measurements could reduce systematics, potentially tightening constraints on the inferred astrophysical parameters.
• In this study, we present forecasts of cross-correlation taking into account the effects of exact uv-sampling and foreground filtering to estimate the feasibility of HERAxSPHEREx making a detection of the 21cm-Ly$\alpha$ cross-power spectrum.