Magnetic field segments (red lines) toward the G31 HMC, obtained by rotating by 90° the polarization segments at 1.3 mm from Beltrán et al. (2019), overlapped on the ALMA 1.4 mm continuum emission map (contours). The segments are sampled every ten pixels. The contours are the same as in Fig. 6a. Negative contours are dotted black. The synthesized beam is shown in the lower left corner. The blue and red crosses indicate the position of the millimeter and/or centimeter sources in the region.