Radial polarized flux profile measured in the Q_φ image per 0.029″(Δx) × 0.290″(Δy) bin (red solid line) compared with profiles of the best-fitting models and background. The background above (green solid line) and below (light green dotted line) the disk midplane and the background in the U_φ image (black solid line) are calculated as explained in Sect. 5. The upper limit is set for the polarized flux per bin for the disk regions beyond r = 0.53″. The arrows “A” and “B” point to the surface brightness peaks.