Emergent radiation at each point in the 128 × 128 pixels FOV in the observation as illustrated in the top panel of Fig. 1. The I, Q, and U signals are shown at the line-center wavelength, while the V signal is shown at Δλ = −0.079 Å from the line center. The white vectors in the intensity panel show the orientation of the linear polarization at the line center. The black and orange dots indicate two particular locations in the FOV analyzed in the text.