Cumulative fraction of signal within a given radius for different models: point-like in black (long-dashed line), isobaric in green, semi-analytical in red, and extended in blue. The distribution of the point-like model follows the MAGIC PSF above 630 GeV. The thin and thick coloured solid lines represent the real and reconstructed (i.e., smeared by the PSF) signal fractions, respectively. The dotted lines represent the fraction of these signals contained in the reference background region. The vertical dashed lines correspond to the used optimum θ_cut values.