Colour-scale map of the Stokes I flux observed by SOFIA. The dashed contours represent N(H₂) column density as derived from Herschel data (levels = [1.0, 1.5, 2.0] × 10²² cm⁻²). The black vectors show the polarisation angles, tilted by 90° to trace the magnetic field direction, and their length is proportional to the polarisation fraction (scale bar in the top left corner). To show statistically independent data, we plot only two vectors per smoothed beam. The smoothed beam size is shown in the bottom left corner. In green, we show the polarisation vectors from optical observations from Franco & Alves (2015). The red and blue arrows indicate the direction of the outflow.