THE FUNDAMENTAL MULTI-BASELINE MODE-MIXING FOREGROUND IN 21 cm EPOCH OF REIONIZATION OBSERVATIONS

This is the authors' abstract. We don't add key points for this paper.

The primary challenge for experiments measuring the neutral hydrogen power spectrum from the epoch of reionization (EoR) is mode-mixing effects, where foregrounds from very bright astrophysical sources interact with the instrument to contaminate the EoR signal. In this paper, we identify a new type of mode mixing that occurs when measurements from non-identical baselines are combined for increased power spectrum sensitivity. This multi-baseline effect dominates the mode-mixing power in our simulations and can contaminate the EoR window, an area in Fourier space previously identified to be relatively free of foreground power.