Two-dimensional constraints of the HI parameters of the 10th frequency channel of the Planck + BINGO likelihood. Panel a shows the consistency across different realizations of of the BINGO simulations. The dotted black lines indicate the truth (fiducial) value of the parameters. Panel b compares the contours for the simulation of the pure 21 cm cosmological signal (blue), simulation including white noise (green), simulation including white noise and foreground removal (red). We find similar shapes and uncertainty levels across the comparisons.