ASTRONOMY COLLOQUIUM

As the Hydrogen Epoch of Reionization Array (HERA) prepares for its final few years of observing in South Africa, its capabilities and limitations are becoming clear. HERA's large dishes and compact array configuration have supported sustained progress in sensitivity and foreground removal, enabling upper limits on the 21-cm power spectrum from cosmic reionization that constrain astrophysics in the early universe. However, these same characteristics limit the reconstruction of 3D intensity maps supporting cross-correlation studies. In this talk, I describe HERA's current limits and exciting forthcoming results, along our recent innovations in calibration and filtering that have the potential to free 21-cm interferometers from the dreaded wedge of chromatic foreground responses. I also describe the new tools that we are working on to design next generation experiments for 21-cm cosmology, and how the landscape of instrument design is changing with the availability of AI technologies.