Small Magellanic Cloud Dust Extinction and Stellar Catalog of ~ 500,000 Individual Sources Modeled with the Bayesian Extinction And Stellar Tool (BEAST)

We use the BEAST open source tool (Gordon et al, 2016) to obtain stellar and dust extinction properties along the line of sight to close to half a million individual sources observed as a part of the SMIDGE survey. The SMIDGE (Small Magellanic Cloud (SMC) Investigation of Dust and Gas Evolution; Yanchulova Merica-Jones 2017, 2021, K. Sandstrom in prep) survey covers a ~ 200pc × 100 pc region in the SW Bar of the SMC and comprises multiband near-UV to near-IR deep HST photometric observations. The BEAST — a probabilistic tool which models the dust-extinguished SEDs of stars using an observational uncertainty model — allows us to derive the dust extinction (A(V), R(V), and fA) and stellar (Teff, mass, surface gravity, luminosity) properties and to generate high-resolution maps in a key region in the SMC. Understanding the properties of dust extinction is fundamental for answering questions ranging from how dust grains form to what drives galaxy evolution. We compare our parsec-scale maps to tracers of the SMC interstellar medium environment (such as HI column density, CO, and dust mass maps from Herschel IR data) to analyze the drivers of dust and stellar properties in a low-metallicity environment. The BEAST (github.com/BEAST-Fitting/) is under active development to allow the study of stellar ensemble properties, such as distance, and enable an understanding of how the 3D structure and the ISM environment influence galactic properties.