Brandon Hensley
(JPL)
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.