Reconstructions with an intensity gradient in the disk (left) and a temperature gradient in the disk ∝ (right). The reconstructions have a χ² ≈ 1. Bottom: cut of the reconstructed images (black) and of the disk models. The colors are for the different wavelengths in the right panel (blue: 1.55 μm, red: 1.8 μm). The flux level is given on a logarithmic scale.