A First Imaging Power Spectrum with the Hydrogen Epoch of Reionization Array Phase II

Abstract

The 21 cm signal from neutral hydrogen is a powerful probe for observing the Epoch of Reionization, a period in cosmological history when the first stars and galaxies were forming. Observing this epoch would give astronomers tremendous insight into the underlying physics driving structure formation in the early universe. However, the 21 cm signal is incredibly faint, and therefore measurements will require high precision instruments and analysis techniques. This thesis works with data from the Hydrogen Epoch of Reionization Array, a radio interferometer designed to observe the 21 cm signal. We present efforts to identify and mitigate instrumental systematics, and explore their direct influence on our ability to achieve successful measurements. Through this, we present new and informative tools for data quality assessment in a many-element interferometer. This includes both statistical and visual data inspection techniques that allow observers to succinctly inspect extremely large volumes of data. Additionally, we make use of interferometric imaging techniques to pursue a power spectrum measurement. This work represents the first imaging-based power spectrum results with HERA phase II. We find a feature that inhibits our power spectrum measurement at some modes, but are noise limited at others. Our results indicate that with a deeper integration HERA has the potential to place scientifically interesting upper limits on the 21 cm signal at some power spectrum modes.