  We present ALMA dust polarization and molecular line observations toward 4
clumps (I(N), I, IV, and V) in the massive star-forming region NGC 6334. In
conjunction with large-scale dust polarization and molecular line data from
JCMT, Planck, and NANTEN2, we make a synergistic analysis of relative
orientations between magnetic fields ($\theta_{\mathrm{B}}$), column density
gradients ($\theta_{\mathrm{NG}}$), local gravity ($\theta_{\mathrm{LG}}$), and
velocity gradients ($\theta_{\mathrm{VG}}$) to investigate the multi-scale
(from $\sim$30 pc to 0.003 pc) physical properties in NGC 6334. We find that
the relative orientation between $\theta_{\mathrm{B}}$ and
$\theta_{\mathrm{NG}}$ changes from statistically more perpendicular to
parallel as column density ($N_{\mathrm{H_2}}$) increases, which is a signature
of trans-to-sub-Alfv\'{e}nic turbulence at complex/cloud scales as revealed by
previous numerical studies. Because $\theta_{\mathrm{NG}}$ and
$\theta_{\mathrm{LG}}$ are preferentially aligned within the NGC 6334 cloud, we
suggest that the more parallel alignment between $\theta_{\mathrm{B}}$ and
$\theta_{\mathrm{NG}}$ at higher $N_{\mathrm{H_2}}$ is because the magnetic
field line is dragged by gravity. At even higher $N_{\mathrm{H_2}}$, the angle
between $\theta_{\mathrm{B}}$ and $\theta_{\mathrm{NG}}$ or
$\theta_{\mathrm{LG}}$ transits back to having no preferred orientation or
statistically slightly more perpendicular, suggesting that the magnetic field
structure is impacted by star formation activities. A statistically more
perpendicular alignment is found between $\theta_{\mathrm{B}}$ and
$\theta_{\mathrm{VG}}$ throughout our studied $N_{\mathrm{H_2}}$ range, which
indicates a trans-to-sub-Alfv\'{e}nic state at small scales as well. The
normalised mass-to-flux ratio derived from the polarization-intensity gradient
(KTH) method increases with $N_{\mathrm{H_2}}$.

Astrophysics of Galaxies