# 3D radiative transfer of intrinsically polarized dust emission based on aligned aspherical grains

## TL;DR

This paper presents a 3D radiative transfer simulation code for polarized dust emission from aligned aspherical grains, aiding the interpretation of observations like those from ALMA to study magnetic fields in protoplanetary disks.

## Contribution

The authors developed a novel 3D radiative transfer code that models intrinsic polarization of dust emission considering grain alignment and shape, enhancing analysis of magnetic fields.

## Key findings

- Polarization maps reveal magnetic field topology.
- Simulations distinguish between thermal polarization effects.
- Disk properties are traced through polarized emission.

## Abstract

(Sub-)Millimeter observations of the polarized emission of aligned aspherical dust grains enable us to study the magnetic fields within protoplanetary disk. However, the interpretation of these observations is complex. One must consider the various effects that alter the measured polarized signal, such as the shape of dust grains, the efficiency of grain alignment, the magnetic field properties, and the projection of the signal along the line of sight. We aim at analyzing observations of the polarized dust emission by disentangling the effects on the polarization signal in the context of 3D radiative transfer simulations. For this purpose, we developed a code capable of simulating dust grain alignment of aspherical grains and intrinsical polarization of thermal dust emission. We find that the influence of thermal polarization and dust grain alignment on the polarized emission displayed as spatially resolved polarization map or as spectral energy distribution trace disk properties which are not traced in total (unpolarized) emission such as the magnetic field topology. The radiative transfer simulations presented in this work enable the 3D analysis of intrinsically polarized dust emission - observed with, e.g., ALMA - which is essential to constrain magnetic field properties.