Orientation vectors of linear polarization with an inclination angle of 75° for a wavelength of λ = 46 μm (left) and λ = 811 μm (right). The parameters are identical to those of BE_hour2. However, the density is n₀ = 10¹² m^-3 in the center and the field strength is 6.0 × 10^-8T. The linear polarization vectors have an offset angle of 90° to match the projected magnetic hourglass field. The orientation angles of linear polarization in the center regions differ from each other because of the 90° flip (see Appendix B).