Brandon Hensley

Dust Polarization in the Microwave: Challenges on the Quest for B-Modes

Polarized emission from Galactic dust has been established as a key foreground in the search for primordial B-modes. Although dust modeling efforts and observations are painting an ever clearer picture of polarized dust emission in the microwave, a number of critical uncertainties remain. First, I will argue that analysis of the latest full-sky Planck maps calls into question the interpretation of anomalous microwave emission as rotational emission from spinning PAHs, thereby opening the door to other mechanisms that may be substantially more polarized. Second, I will describe current efforts to construct a comprehensive model of dust polarization by synthesizing data from the ultraviolet to the radio, focusing on the implications for the frequency-dependence of the polarized dust emission. Finally, I will suggest observations that could mitigate key uncertainties in the dust physics and enable higher fidelity foreground modeling.