The Role of Magnetic Fields in the Formation of the Filamentary Infrared Dark Cloud G11.11–0.12

We report on the near-infrared polarimetric observations of G11.11-0.12 (hereafter G11) obtained with SIRPOL 1.4 m IRSF telescope. The starlight polarisation background stars reveals on-sky component magnetic fields in G11, and these are consistent field orientation observed from polarised dust emission at $850\,\mu$m. G11 perpendicular to filament, independent filament's relative Galactic plane. strength envelope is range $50-100\,\mu$G, derived two methods. analyses gas velocity dispersion indicate that supersonic but sub-Alfv{\'e}nic. critical mass-to-flux ratio close 1 increases $\gtrsim 1$ spine G11. weights importance fields, turbulence gravity dominates dynamical state significant contribution fields. strength, $|\mathbf{B}|$, slower than density, $n$, characterized by $|\mathbf{B}|\propto n^{0.3}$. imply sub-Alfv{\'e}nic flow channelled strong assembled into filaments formation low-mass enhanced high column agreement excess protostars detected densest regions