Maps of the extended (top) and compact (bottom) components that contribute to the FIR continuum emission of SDSS J1148+5251 at average rest-frame wavelength λ = 155 μm. The map of the extended component has been obtained by subtracting, from the uv data, the point source model of the compact component resulting from the uv fit reported in Fig. 11. The map of the compact component has been obtained by applying a uv tapering that cuts visibilities with uv radius <100 m, therefore slightly increasing the resolution of the data (the resulting beam size is 0.99′′×0.89′′). In the map of the extended component, contours correspond to − 3σ, 3σ, 5σ to 9σ in steps of 2σ (1σ rms noise is 0.082 mJy beam^-1). For the compact component, contours correspond to − 3σ, 3σ, 5σ to 25σ in steps of 5σ (1σ rms noise is 0.088 mJy beam^-1). In both panels, the cross indicates the pointing and phase centre, corresponding to the optical position of the quasar.