Extended Data Figure 8: Residuals to the 21-cm profile model.
From: An absorption profile centred at 78 megahertz in the sky-averaged spectrum
The black curve shows the best-fitting 21-cm profile model derived from the observations. The solid blue and yellow curves show fits to the model profile using the physical (equation (1)) and five-term polynomial (equation (2)) foreground models, respectively. The dashed lines show the residuals after subtracting the fits from the model. These residuals are similar to those found when fitting the observations using only a foreground model (Fig. 1b).
