New constraints on the Polarization of Anomalous Microwave Emission in nearby molecular clouds

Understand

Anomalous Microwave Emission (AME) has been previously studied in two well-known molecular clouds and is thought to be due to electric dipole radiation from small spinning dust grains.

• It is important to measure the polarization properties of this radiation both for component separation in future cosmic microwave background experiments and also to constrain dust models.
• We have searched for linearly polarized radio emission associated with the $\rho$ Ophiuchi and Perseus molecular clouds using {\it WMAP} 7-year data.
• We found no significant polarization within an aperture of $2^{\circ}$ diameter.