Exploring the Effects of Foreground Removal Techniques and Instrumental Systematics on Observations of the 21 cm Neutral Hydrogen Signal

Abstract

There is a substantial and growing interest in cosmology to study the 21 cm signal emitted or absorbed by large abundances of neutral hydrogen (HI) in the vast cosmic web of the universe.  Such study has the potential to allow scientists to map the matter distribution of the universe over nearly its entire history.  However, in order to unlock this rich potential, one must develop the ability to distinguish and remove large contaminating signals from ionized gas in the foregrounds of the 21 cm signal in addition to having high precision control of instrumental systematics.  As such, we first understand and construct the associated ability to remove four common astrophysical foregrounds to 21 cm experiments.  We then assess the degree to which three common instrumental systematics introduce systematic un-smoothing effects into the analysis of these astrophysical foregrounds.  This study works within the framework of simulated Green Bank Telescope radio beam data.