Jia-Wei Wang (National Tsing Hua University), Shih-Ping Lai (National Tsing Hua University), and the BISTRO Consortium
How the magnetic field strength varies with the volume density is an indicator of whether the magnetic field is important in control the cloud collapsing. In this talk, I would present the detailed magnetic field strength map estimated from our optical, NIR, and submm polarization data. We found that the cloud is magnetically subcritical in the outer layer, traced by optical polarization data, and gradually becomes supercritical in the interior of the cloud, traced by the NIR and submm data. In addition, the estimated magnetic field strength varies with the volume density following a power-law with index of 0.48, suggesting that the cloud collapsing is regulated by the magnetic fields. Our results suggest that the magnetic field is dynamically important in formation of the filamentary cloud, but gradually be dominated by gravity in the dense regions.