Fourier scale dependent functions applied in the classical feathering technique (Stanimirovic 2002). The blue (red) solid line shows the Planck (Herschel at 160 μm) beam approached by a Gaussian of 5′ (12″) in the Fourier domain. The green line shows the scale-dependent functions applied to the Herschel data following the classical feathering algorithm (see Sect. 3.2). The dotted red (blue) line shows the interpolationg functions used in this paper for Herschel, (Planck, ) assuming κ_eff = 5′. The functional form of these interpolation functions is shown in Eq. (A.1) (Eq. (A.2)).