摘要
The hierarchical interplay among gravity, magnetic fields, and turbulence in forming massive protostellar clusters remains elusive. We present high-resolution (similar to 14 arc seconds similar or equal to 0.05 parsecs), 850-micrometer dust polarization and (CO)-O-18 line observations of Cepheus A using JCMT SCUBA-2/POL-2 and HARP. Our analysis reveals aligned gravitational (G), magnetic (B), and velocity fields (K), with an energy hierarchy of E-G > E-B > E-K. Gravity, as the primary driver, induces gas flows and drags in B-field lines. Magnetic tension, as a secondary force, regulates turbulence, enabling ordered flows with an accretion rate of similar to 2.1 +/- 0.4 x 10(-4) M-circle dot per year. This challenges the conventional view of B-fields resisting collapse in the clump/hub scale, instead showing cooperation with gravity. The similar to 0.6-parsec clump-scale B-field (with a mean position angle of similar to 45 degrees) aligns coherently with fields at cloud (similar to 5 parsecs), core (similar to 0.05 parsecs), and disk (similar to 2000 astronomical units) scales, offering key insights into the role of magnetic fields in multiscale star formation dynamics.