Spinning Dust Emission from Wobbling Grains: Important Physical Effects and Implications

TL;DR

This review discusses advanced physical effects influencing spinning dust emission from tiny grains, improving models to better understand their properties and polarization in astrophysical environments.

Contribution

The paper introduces new physical effects into spinning dust models, such as grain wobbling and impulsive ion collisions, enhancing the accuracy of emission predictions.

Findings

Inclusion of grain wobbling affects emission spectra.

Impulsive ion collisions significantly influence grain rotation.

Potential polarization of spinning dust emission discussed.

Abstract

We review major progress on the modeling of electric dipole emission from rapidly spinning tiny dust grains, including polycyclic aromatic hydrocarbons (PAHs). We begin by summarizing the original model of spinning dust proposed by Draine and Lazarian and recent theoretical results improving the Draine and Lazarian model. The review is focused on important physical effects that were disregarded in earlier studies for the sake of simplicity and recently accounted for by us, including grain wobbling due to internal relaxation, impulsive excitation by single-ion collisions, the triaxiality of grain shape, charge fluctuations, and the turbulent nature of astrophysical environments. Implications of the spinning dust emission for constraining physical properties of tiny dust grains and environment conditions are discussed. We discuss the alignment of tiny dust grains and possibility of polarized spinning dust emission. Suggestions for constraining the alignment of tiny grains and polarization of spinning dust emission are also discussed.