The role of magnetic fields in the star-formation process is poorly understood, mainly due to significant limitations in observing three-dimensional (3D) magnetic fields in the interstellar medium (ISM). In this talk, I will discuss our work on observing the 3D magnetic field morphology associated with molecular clouds.
To determine the 3D fields, we first developed a novel technique for probing the line-of-sight strength and direction of magnetic fields associated with molecular clouds, based on Faraday rotation measurements. We then incorporated our line-of-sight and Planck’s plane-of-sky magnetic field observations, along with models and statistical tools, to study the 3D magnetic field morphology associated with the Orion A cloud. Finally, we used Galactic magnetic field models to reconstruct the complete 3D magnetic field morphologies, including their direction (associated with the Orion A and Perseus clouds). I will discuss these techniques, our results, and their connection to larger ISM magnetic fields, in this talk.