Model images of the polarized flux from HD 172555 debris disk. Images were generated using the parameters of mean model (Col. 5 in Table 2) and illustrate the individual steps of the modeling procedure (from left to the right panels) to obtain the final synthetic Q_φ and U_φ images (panels g and h). For a detailed description of the presented images, see Appendix A. The diagram on the right side of the figure explains orientation of the axes used to measure the Stokes Q and U parameters as implemented in ZIMPOL instrument. The diagram shows also the orientation of north and east in each image. The north is rotated by 22° clockwise from the vertical line to have disk axis in horzontal position. Nonalignment of the disk axes with the Q and U measuring axes causes asymmetric flux distribution in Q and U images (panels c–f).