Contour plot of the polarization angle vs. polarization degree accounting for the 68%, 90%, and 99% confidence levels, computed by taking into account the IXPE I, Q, and U spectra in the 2–5.5 keV band (the energy band with the highest significance in terms of polarization detection). The orange cross indicates the best-fit values of P and Ψ, which are also reported in the lower left corner. The dashed blue line describes the direction of the parsec-scale radio jet (Wilson & Ulvestad 1983). The dashed brown line indicates the orientation of the molecular torus derived by García-Burillo et al. (2019) with ALMA (see Sect. 4.1).