The Dust & Gas Properties of M83

TL;DR

This study analyzes the dust and gas properties of galaxy M83, revealing spatial variations in dust temperature, mass, and their relation to gas and star formation, with implications for understanding galactic structure and composition.

Contribution

It provides detailed spatial mapping of dust and gas properties in M83, including the gas-to-dust ratio and its variation with metallicity, using Herschel, JCMT, and THINGS data.

Findings

Dust temperature peaks ahead of dust mass in spiral arms.

Gas-to-dust ratio averages 84 with regional variations.

Dust correlates with molecular gas and star formation regions.

Abstract

We examine the dust and gas properties of the nearby, barred galaxy M83, which is part of the Very Nearby Galaxy Survey. Using images from the PACS and SPIRE instruments of Herschel, we examine the dust temperature and dust mass surface density distribution. We find that the nuclear, bar and spiral arm regions exhibit higher dust temperatures and masses compared to interarm regions. However, the distribution of dust temperature and mass are not spatially coincident. Assuming a trailing spiral structure, the dust temperature peaks in the spiral arms lie ahead of the dust surface density peaks. The dust mass surface density correlates well with the distribution of molecular gas as traced by CO (J=3-2) images (JCMT) and the star formation rate as traced by H?2 with a correction for obscured star formation using 24 micron emission. Using HI images from THINGS to trace the atomic gas component, we make total gas mass surface density maps and calculate the gas-to-dust ratio. We find a mean gas-to-dust ratio of 84 \pm 4 with higher values in the inner region assuming a constant CO-to-H2 conversion factor. We also examine the gas-to-dust ratio using CO-to-H2 conversion factor that varies with metallicity.