2001ApJ...546L..53G

Molecular outflows from young protostars are widely believed to be collimated by magnetic fields, but there has been little observational evidence to support this hypothesis. Using the new technique of millimeter-wavelength spectropolarimetry, we demonstrate the existence of a magnetic field in the NGC 2024 FIR 5 outflow lobe. The 1.3 mm J=2-1 transition of carbon monoxide (CO) is polarized at a level of approximately 1%, in a direction within 10°-15° of the outflow axis. This agrees with theoretical models in which the magnetic field channels the outflowing gas, and it shows that the process can be effective as far as 0.1 pc from the protostar.