Two-dimensional histogram of the standardized error (Eq. (24)) for the point sources. The histogram is plotted together with the lowest detection threshold, θ = 2.5 × 10⁻⁹, calculated for the region with the longest observation time in Appendix C. The colorbar shows the counts per bin in the two-dimensional histogram, i.e., higher values correspond to more frequent combinations of standardized error and ground truth flux.