A refined model for spinning dust radiation

TL;DR

This paper refines the model of spinning dust radiation by updating physical parameters, computing grain velocity distributions, and analyzing environmental effects, with an implementation in the SPDUST code.

Contribution

It provides an improved, comprehensive model of spinning dust emission incorporating updated physics and grain properties, and makes the code publicly available.

Findings

Updated grain optical properties and size distributions.

Analysis of environmental effects on emissivity.

Implementation of the model in SPDUST code.

Abstract

We present a comprehensive treatment of the spectrum of electric dipole emission from spinning dust grains, updating the commonly used model of Draine and Lazarian. Grain angular velocity distributions are computed using the Fokker-Planck equation; we revisit the drift and diffusion coefficients for the major torques on the grain, including collisions, grain-plasma interactions, and infrared emission. We use updated grain optical properties and size distributions. The theoretical formalism is implemented in the companion code, SPDUST, which is publicly available. The effect of some environmental and grain parameters on the emissivity is shown and analysed.