Best fits for modeled toroidal and helical fields. Colored lines represent the modeled x, y, and z components of the magnetic field. The colored symbols represent the x, y, and z components of the observed magnetic field. On x-axis, X isthe perpendicular distance from the filament’s long axis, and L is the LOS integration distance. The two α values are the parameters explained in Sect. 3.2. The different B₁ /B₀ ratios arise from Eq. (2) and set the level of helicity, with B₁/B₀ = 0 indicating a purely toroidal field.