High-resolution synthetic UV-submm images for simulated Milky Way-type galaxies from the Auriga project

TL;DR

This paper creates realistic high-resolution synthetic UV to sub-millimeter images of simulated Milky Way-like galaxies from the Auriga project, incorporating dust effects and comparing them with real observations.

Contribution

It introduces a detailed post-processing method using SKIRT to generate synthetic images, considering different dust assignment mechanisms and providing publicly available multi-wavelength data.

Findings

Auriga galaxies show good overall agreement with observations in dust properties.

Simulated galaxies are slightly more dust-rich than observed counterparts.

Morphological comparisons reveal similarities and differences across wavelengths.

Abstract

We present redshift-zero synthetic observational data considering dust attenuation and dust emission for the thirty galaxies of the Auriga project, calculated with the SKIRT radiative transfer code. The post-processing procedure includes components for star-forming regions, stellar sources, and diffuse dust taking into account stochastic heating of dust grains. This allows us to obtain realistic high-resolution broadband images and fluxes from ultraviolet to sub-millimeter wavelengths. For the diffuse dust component, we consider two mechanisms for assigning dust to gas cells in the simulation. In one case, only the densest or the coldest gas cells are allowed to have dust, while in the other case this condition is relaxed to allow a larger number of dust-containing cells. The latter approach yields galaxies with a larger radial dust extent and an enhanced dust presence in the inter-spiral regions. At a global scale, we compare Auriga galaxies with observations by deriving dust scaling relations using SED fitting. At a resolved scale, we make a multi-wavelength morphological comparison with nine well-resolved spiral galaxies from the DustPedia observational database. We find that for both dust assignment methods, although the Auriga galaxies show a good overall agreement with observational dust properties, they exhibit a slightly higher specific dust mass. The multi-wavelength morphological analysis reveals a good agreement between the Auriga and the observed galaxies in the optical wavelengths. In the mid and far-infrared wavelengths, Auriga galaxies appear smaller and more centrally concentrated in comparison to their observed counterparts. We publicly release the multi-observer images and fluxes in 50 commonly used broadband filters.