The Spatial Distribution of Dust and Stellar Emission of the Magellanic Clouds

TL;DR

This study maps and analyzes the spatial distribution of dust and stellar emission in the Magellanic Clouds, revealing how dust/stellar ratios vary with environment and star formation activity.

Contribution

It provides detailed spatially resolved maps of dust and stellar luminosity and mass in the Magellanic Clouds, linking dust properties to star formation and ISM conditions.

Findings

Dust/stellar luminosity ratios vary across galaxies.

Dust/stellar ratios depend on ISM environment and radiation field.

Star formation rate correlates with dust emission and temperature.

Abstract

We study the emission by dust and stars in the Large and Small Magellanic Clouds, a pair of low-metallicity nearby galaxies, as traced by their spatially resolved spectral energy distributions (SEDs). This project combines Herschel Space Observatory PACS and SPIRE far-infrared photometry with other data at infrared and optical wavelengths. We build maps of dust and stellar luminosity and mass of both Magellanic Clouds, and analyze the spatial distribution of dust/stellar luminosity and mass ratios. These ratios vary considerably throughout the galaxies, generally between the range $0.01\leq L_{\rm dust}/L_\ast\leq 0.6$ and $10^{-4}\leq M_{\rm dust}/M_\ast\leq 4\times10^{-3}$. We observe that the dust/stellar ratios depend on the interstellar medium (ISM) environment, such as the distance from currently or previously star-forming regions, and on the intensity of the interstellar radiation field (ISRF). In addition, we construct star formation rate (SFR) maps, and find that the SFR is correlated with the dust/stellar luminosity and dust temperature in both galaxies, demonstrating the relation between star formation, dust emission and heating, though these correlations exhibit substantial scatter.