Monoceros OB 1 east region observed by Planck and TRAO. Left panel: Planck 353 GHz intensity map in MJy sr⁻¹ at the angular resolution of 7′ with the POS magnetic field orientation overlaid as blue segments. The length of the segments corresponds to polarization fraction, with the reference length of 15′ corresponding to p = 0.05 (shown in the red box in the bottom right corner). Only data satisfying S/N (p) ≥ 2 and σ_ψ < 10° are used for polarization studies. Red, yellow, and green lines show contours of the TRAO map used in this analysis, the northern region (Fig. 5), and the southern region (Fig. 10) respectively. The pink dashed line shows the isolatitude b_II = 0°. Right panel: TRAO ¹²CO (J=1−0) integrated (between v_lsr = −3 and 17 km s⁻¹) intensity map in K km s⁻¹ at angular resolution of 47′′ with the POS magnetic field orientation derived from the Planck data overlaid as blue segments. Red contour corresponds to the red contour in the left panel.