Adaptable Radiative Transfer Innovations for Submillimetre Telescopes (ARTIST) - Dust polarisation module (DustPol)

TL;DR

DustPol is a new publicly available tool within the ARTIST package that models polarized thermal dust emission, aiding the interpretation of submillimetre observations from telescopes like ALMA and Planck.

Contribution

The paper introduces DustPol, a novel module for modeling polarized dust emission, integrated into the ARTIST radiative transfer package, with capabilities for synthetic map generation and analysis.

Findings

DustPol can generate synthetic Stokes maps in FITS format.

Depolarization occurs at densities above 10^6 cm^-3 in prestellar cores.

Model results are consistent with observations of NGC 1333 IRAS 4A.

Abstract

We present a new publicly available tool (DustPol) aimed to model the polarised thermal dust emission. The module DustPol, which is publicly available, is part of the ARTIST (Adaptable Radiative Transfer Innovations for Submillimetre Telescopes) package, which also offers tools for modelling the polarisation of line emission together with a model library and a Python-based user interface. DustPol can easily manage analytical as well as pre-gridded models to generate synthetic maps of the Stokes I, Q, and U parameters. These maps are stored in FITS format which is straightforwardly read by the data reduction software used, e.g., by the Atacama Large Millimeter Array (ALMA). This turns DustPol into a powerful engine for the prediction of the expected polarisation features of a source observed with ALMA or the Planck satellite as well as for the interpretation of existing submillimetre observations obtained with other telescopes. DustPol allows the parameterisation of the maximum degree of polarisation and we find that, in a prestellar core, if there is depolarisation, this effect should happen at densities of 10^6 cm-3 or larger. We compare a model generated by DustPol with the observational polarisation data of the low-mass Class 0 object NGC 1333 IRAS 4A, finding that the total and the polarised emission are consistent.