Joint Astrophysics Colloquium

Studying Star Formation from the Stratosphere

Laura Fissel

National Radio Astronomy Observatory

The conversion of interstellar molecular gas into stars is an extremely inefficient process, due to regulation from a combination of turbulent gas motions, magnetic fields, and feedback from young stars. Of these the role played by magnetic fields is particularly poorly understood, largely because of the difficulty of making direct observations. In this talk I will discuss what we have learned about magnetic fields in star-forming regions using the Balloon-borne Large Aperture Sub-mm Telescope for Polarimetry (BLASTPol). BLASTPol operated from 38km above the Earth’s surface (above 99.5% of the atmosphere), mapping polarized radiation at sub-mm wavelengths from dust grains aligned with their local magnetic field. By statistically comparing BLASTPol-inferred magnetic field maps of the nearby giant molecular cloud Vela C with simulations, we find that magnetic fields play an important role in the formation of both low- and high-density molecular gas sub-structures. I will finish by presenting our next-generation balloon-borne polarimeter, BLAST-TNG, which is scheduled for a first Antarctic flight this December. With BLAST-TNG we will map dozens of molecular clouds at 5x better resolution and quantitatively determine the extent to which magnetic fields affect star formation efficiency.