Predicting the stellar and non-equilibrium dust emission spectra of high-resolution simulated galaxies with DART-Ray

TL;DR

This paper introduces DART-Ray, a 3D ray-tracing code for calculating dust emission spectra in galaxies, utilizing an adaptive SED library to efficiently model non-equilibrium dust emission in high-resolution galaxy simulations.

Contribution

The paper presents a novel adaptive SED library approach within DART-Ray, enabling efficient computation of dust emission spectra in complex galaxy geometries.

Findings

DART-Ray accurately predicts galaxy appearance from UV to sub-mm wavelengths.

Dust significantly affects observed stellar profiles and light attenuation.

The model quantifies dust re-radiation contributions from young and old stars.

Abstract

We describe the calculation of the stochastically heated dust emission using the 3D ray-tracing dust radiative transfer code DART-Ray, which is designed to solve the dust radiative transfer problem for galaxies with arbitrary geometries. In order to reduce the time required to derive the non-equilibrium dust emission spectra from each volume element within a model, we implemented an adaptive SED library approach, which we tested for the case of axisymmetric galaxy geometries. To show the capabilities of the code, we applied DART-Ray to a high-resolution N-body+SPH galaxy simulation to predict the appearance of the simulated galaxy at a set of wavelengths from the UV to the sub-mm. We analyse the results to determine the effect of dust on the observed radial and vertical profiles of the stellar emission as well as on the attenuation and scattering of light from the constituent stellar populations. We also quantify the proportion of dust re-radiated stellar light powered by young and old stellar populations, both bolometrically and as a function of infrared wavelength.