Light contribution of the host galaxy and the polar disk. Upper panel: the long-slit luminosity profile (instrumental surface brightness) obtained by collapsing the long-slit spectrum (PA = 152°) along the wavelength direction in the 8500 <λ< 8800 region. The profile is decomposed into the contribution of a Sersic profile (associated to the host galaxy, in blue) and an exponential disk (associated to the polar disk, in red). Bottom panel: fractional contribution of the host galaxy (F₁, in blue) and the polar disk (F₂, in red) with respect to the median galaxy flux (normalized to 1). For a given radial bin R, the spectral decomposition code computes the best fit value in the interval (which is represented by the shaded regions in the lower panel), and it assumes F_1,2 = 0.2 as detection limit for a component (represented by the dashed horizontal line). See Sect. 3 for details.