CMB Polarization due to Scattering in Clusters

Scattering of the cosmic microwave background (CMB) in clusters of galaxies polarizes the radiation. We explore several polarization components which have their origin in the kinematic quadrupole moments induced by the motion of the scattering electrons, either directed or random. Polarization levels and patterns are determined in a cluster simulated by the hydrodynamical Enzo code. We find that polarization signals can be as high as $\sim 1 \mu$K, a level that may be detectable by upcoming CMB experiments.