Mitchell Institute for Fundamental Physics & Astronomy
College Station, Texas 77843
Magnetic fields are known to play an important role in the process of star formation. Class I methanol masers are generally found in outflows associated with star forming regions where the collisional shocks pump the maser transitions. They may offer unprecedented opportunities for measuring the large-scale magnetic field in these regions through the Zeeman effect. Such measurements would be possible because of connections between the large-scale magnetic field in the pre-shock regions and the observed magnetic field along the outflows in the post-shock regions where these masers are formed. The enhanced capabilities of the Very Large Array (VLA) through the Expanded VLA project were instrumental in the discovery of the Zeeman Effect in the Class I Methanol maser transitions at 25, 36, and 44 GHz, opening an exciting new window into the study of the star formation process. In this talk, I will give a brief overview of the VLA, describe the Zeeman Effect and the calibration techniques to measure the line-of-sight magnetic field in circular polarization observations, and present the discovery of, and the follow up results on the Zeeman Effect in Class I methanol masers and their importance as signposts to measure the large scale magnetic fields in star forming regions.