The observed data for a) NGC 4151, b) NGC 3783, and c) ESO323-G77 (see Sect. 2), and the best fits using a temperature/density gradient model plus an inner 1400 K ring (see Sect. 4.4 and Table 8). Top: spectral energy distribution in . The data plotted in black are the total flux measurements from MIDI and VISIR in the mid-IR and from WFCAM or 2MASS in the near-IR. Additional total flux spectra and photometry from Spitzer (Table 4) are plotted in gray. For NGC 3783, ISAAC photometry data (Table 4) are shown as gray squares. Correlated fluxes from the mid-IR and near-IR interferometry are plotted with colors coded on spatial wavelengths in units of R_in as shown in the top color bar. The model curves for the total flux and the correlated fluxes at baselines corresponding to each MIDI observation are drawn in the same color coding. Middle: visibility amplitude plotted against spatial frequency in units of cycles per R_in. The color of the data points corresponds to the observing wavelength in the rest frame of the target. This color-coding is shown as a color bar between the middle and bottom panels. The iso-wavelength model visibility curves are shown for 13, 8.5, and 2.2 μm, as well as the curves for each baseline configuration (which are “orthogonal” to the iso-wavelengh curves). Dotted curves are the visibilities only for the power-law component, with the difference from solid curves indicating the effect of the near-IR ring. For NGC 3783, solid and dashed model curves are for equatorial and polar axis PAs, respectively (see Sect. 4.3). Bottom: the uv coverage of the mid-IR and near-IR interferometry with the same color-coding on observing wavelengths. Solid and dashed lines indicate the PA of the projected equatorial and polar axes, respectively, inferred from optical polarization and radio data (see Table 5).