Polarization degree and angle measured in spatial bins (subslits) along the slit. The polarization degree is not corrected for the bias. The bin centered on the nucleus is 5 spatial pixels (1.25″) long. The subsequent bins are 3, 3, 5, 6, and 7 pixels long. Positive distances are toward the north, negative ones toward the south (1″≃ 380 pc). Measurements integrated over the continuum wavelength ranges 3800–5000 Å< and 5400–6600 Å are shown in blue and red, respectively. The bin at −4.1″ contains the southern spot.