Full-Sky Models of Galactic Microwave Emission and Polarization at Sub-arcminute Scales

Polarized foreground emission from the Galaxy is one of the biggest challenges facing current and 34 upcoming cosmic microwave background (CMB) polarization experiments. We develop new models 35 of polarized Galactic dust and synchrotron emission at CMB frequencies that draw on the latest 36 observational constraints, that employ the “polarization fraction tensor” framework to couple intensity 37 and polarization in a physically motivated way, and that allow for stochastic realizations of small-scale 38 structure at sub-arcminute angular scales currently unconstrained by full-sky data. We implement these 39 models into the publicly available Python Sky Model (PySM) software and additionally provide PySM 40 interfaces to select models of dust and CO emission from the literature. We characterize the behavior of 41 each model by quantitatively comparing it to observational constraints in both maps and power spectra, 42 demonstrating an overall improvement over previous PySM models.