Anomalous Microwave Emission from Spinning Dust and its Polarization Spectrum

TL;DR

This paper reviews the improved models of spinning dust as the source of anomalous microwave emission (AME), discusses recent progress in understanding its polarization, and highlights remaining questions about AME's origins.

Contribution

It introduces an enhanced spinning dust model incorporating realistic grain dynamics and impulsive ion interactions, advancing understanding of AME's polarization characteristics.

Findings

Spinning dust emission is consistent with observations of AME.

Recent models account for wobbling non-spherical grains and impulsive interactions.

Progress has been made in quantifying the polarization of spinning dust emission.

Abstract

Nearly twenty years after the discovery of anomalous microwave emission (AME) that contaminates to the cosmic microwave background (CMB) radiation, its origin remains inconclusive. Observational results from numerous experiments have revealed that AME is most consistent with spinning dust emission from rapidly spinning ultrasmall interstellar grains. In this paper, I will first review our improved model of spinning dust, which treats realistic dynamics of wobbling non-spherical grains, impulsive interactions of grains with ions in the ambient plasma, and some other important effects. I will then discuss recent progress in quantifying the polarization of spinning dust emission from polycyclic aromatic hydrocarbons. I will finish with a brief discussion on remaining issues about the origins of AME.