Map-by-map comparison of the results from the different estimators for local (left), equilateral (centre), and orthogonal (right) f_NL (taking the shapes to be independent), for the third set of simulations described in Sect. 5.1, including both noise and a mask. Results are shown for T-only (top), E-only (centre), and the full combined T+E case (bottom). The legend for the estimators can be found in the top right figure. The horizontal solid line is the average value of all maps for KSW, and the dashed and dotted horizontal lines correspond to ± 1σ and ± 2σ deviations, respectively.