The Spatial Distribution of Dust and Stellar Emission of the Magellanic Clouds
Bot, Caroline; Lebouteiller, Vianney; Bernard, Jean-Philippe; Meixner, Margaret; Sauvage, Marc; Roman-Duval, Julia; Babler, Brian; Galametz, Maud; Hony, Sacha; Israel, Frank; Li, Aigen; Madden, Suzanne; Misselt, Karl; Montiel, Edward; Okumura, Koryo; Panuzzo, Pasquale; Seale, Jonathan; Rubio, Mónica; Engelbracht, Charles W.; Skibba, Ramin A.; van Loon, Jacco Th.; Galliano, Frédéric; Gordon, Karl; Paradis, Deborah; Aniano, Gonzalo; Carlson, Lynn Redding; Srinivasan, Sundar
United States, France, Netherlands, United Kingdom, Chile
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. This project combines Herschel Space Observatory PACS and SPIRE far-infrared photometry with other data at infrared and optical wavelengths (the data were obtained as part of the HERschel Inventory of The Agents of Galaxy Evolution survey; PI: M. Meixner). We build maps of dust, 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 <= L dust/L * <= 0.6 and 10-4 <= M dust/M * <= 4 × 10-3. We observe that the dust/stellar ratios depend on the interstellar medium environment, such as the distance from currently or previously star-forming regions, and on the intensity of the interstellar radiation field. 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.