2026ApJ...998..330L

We present the Atacama Large Millimeter/submillimeter Array observations of linearly polarized 870 μm continuum emission at ∼0$\mathop{.}\limits^{^{\prime\prime} }$2 (2000 au) resolutions toward the two massive clumps, Clump 1 and Clump 4, in the 20 km s^–1 cloud. The derived magnetic field strength for both clumps ranges from ∼0.3 to 3.1 mG using the angular dispersion function method. The magnetic field orientations across multiple scales suggest that the magnetic field dominates at the cloud scale, whereas gravity appears to govern structures at the core (0.01-0.1 pc) and condensation (≤0.01 pc) scales. Furthermore, the study on the angular difference between the orientations of the local gravity gradient and the magnetic field suggests that the magnetic field predominantly governs the dynamics in the diffuse regions, while gravity and star formation feedback become increasingly significant within the dense regions. The ratio of the magnetic field tension force F_B to the gravitational force F_G suggests that the magnetic field may provide some support against gravity, but it is insufficient to prevent gas from infalling toward the dense cores.