HST/FOC observation of Mrk 463E resampled to pixels of 0.05″ × 0.05″. The intensity is color-coded in erg cm⁻² s⁻¹ Å⁻¹. The polarization vectors are displayed for Conf_P ≥ 99%. The dark gray contour and cross, as well as the red cross, show our estimates for the nucleus location and are discussed in Sect. 3.1 and Appendix B. The flux density contours are displayed for 0.8%, 2%, 5%, 10%, 20%, and 50% of the maximum flux density. The top left corner values are integrated over the whole FOC FoV (7″ × 7″): F_λ^int = (17.81 ± 0.02)×10⁻¹⁶ ergs cm⁻² s⁻¹ Å⁻¹ with P^int = 8.8 ± 0.2% and Ψ^int = 88.3 ± 0.5°. The circled spots are discussed in Sect. 3.1.