Application of the PFVG method to the object Mrk 509 for epochs 2016 (left) and 2017 (right). The black dots correspond to the median of the recovered distributions of host galaxy fluxes (see Fig. A.4). The error bars show the formal 1σ uncertainty around the median. The results obtained by the FVG are shown with open blue squares. The redshifted bulge galaxy template of Kinney et al. (1996) is fitted to both PFVG (red) and FVG (blue) host-galaxy fluxes. The fit residuals, as obtained for the PFVG and FVG, are shown in the bottom panels. A small wavelength shift between the PFVG and FVG was introduced for clarity.