Histogram density plot of randomly placed 10 000 apertures over a 5″ × 5″ F390W image centered on Ion3. The black line is the Gaussian fit to the measured fluxes (in ADU) from 10 k apertures, with a resulting mean value of 0.001 and a 1σ of 0.0119, marked with a red dashed line (2σ and 3σ are marked with yellow and green dashed lines, respectively). The thick blue dashed line represents the background-subtracted, clean, non-contaminated LyC signal of Ion3, while thin gray dashed line is measured non-contaminated LyC signal before the background subtraction.