Wednesday, November 17, 2010 - 3:15pm
"Resolved Studies of the Abundance & Characteristics of Interstellar Dust within Nearby Galaxies"
Abstract. Dust plays key roles in the interstellar medium (ISM), but we do not yet clearly understand what determines its abundance, composition and size distribution. These characteristics will be a function of the formation, destruction and processing that grains receive in the ISM, i.e. the life-cycle of dust. With the recent availability of high angular resolution infrared observations of nearby galaxies from Spitzer and Herschel, we can start to address the unknown aspects of the dust life-cycle by studying the variations of dust abundance and composition as a function of the ISM conditions within a galaxy. In this talk I will present results from two studies of the resolved dust properties in nearby galaxies. First I will discuss measurements of the dust-to-gas ratio (DGR) and CO-to-H2 conversion factor in a sample of galaxies observed as part of the HERACLES CO survey and the KINGFISH key-program on Herschel. These new surveys allow us to study the DGR over a wide range of metallicities and ISM conditions. Next, moving to the low-metallicity regime, I will discuss spatial variations in the dust composition and abundance in the Small Magellanic Cloud and what they tell us about the formation and evolution of dust at low-metallicity.