Oral Presentation

Starlight Polarimetry and Thermal Dust Emission Polarimetry versus Zeeman Effect B-Field Strengths: Progress and Plans

Author(s): Dan Clemens (Boston University), Adham El-Batal (Boston University), Thushara Pillai (Boston University)

Presenter: Dan Clemens (Boston University)

Background starlight polarimetry (BSP) in the near-infrared, as measured using the Mimir instrument, and thermal dust emission polarimetry (TEP), from the HAWC+ instrument on SOFIA, offer ready access to magnetic field properties in molecular clouds and their dense cores. However, field strength values from these methods rely on the Davis-Chandrasekhar-Fermi method and the assumptions it contains. Zeeman Effect field strengths from circular polarization of atomic and molecular spectral lines are best, but they have their own significant limitations and are very expensive to obtain. Our program to cross-calibrate BSP/TEP to Zeeman Effect field strengths covers three orders of magnitude, using deep Mimir observations as well as new, ongoing, and future HAWC+ observations. Some early results are promising and this talk will summarize the methods, cloud and core samples employed, and the future work that will complete this calibration which is so vital to our entire field.