Standard deviation for all maps as a function of the peak S/N of the sources. The blue-shaded region indicates the standard deviation over the various noise estimates from the 50 jackknife realizations for each S/N. The orange-shaded region is the standard deviation over the orange data points in Fig. 5. By jackknifing the observations, we retrieve the noise properties of the cleaned map accurately when the sources have S/N < 50.