Abstract
Transformative Studies of Stellar Dust Production with JWST: The DUSTiNGS Pathfinding Surveys
Martha Boyer (STScI)
The DUSTiNGS Team
Studies of the Milky Way and Magellanic Clouds suggest that evolved stars such as Asymptotic Giant Branch (AGB) stars and red supergiants supply a sizable fraction of a galaxy's infrared flux and inject significant amounts of dust into the interstellar medium, rivaling the dust injected by supernovae. Determining the effect of environment on stellar dust production is therefore essential for understanding the role evolved stars play in the chemical enrichment and dust evolution of galaxies and the effect these stars have on the observable properties of their host galaxies. The James Webb Space Telescope will, for the first time, enable the detection and spatial resolution of entire evolved stellar populations in star-forming galaxies more distant than the Magellanic Clouds at wavelengths where dust emission peaks (5-20 microns). The diverse sample of galaxies reachable with JWST and its unique capabilities will allow for an unbiased analysis of the effects of metallicity and age on the dust chemistry and formation efficiency, which are currently unconstrained and highly uncertain. I will describe some preparatory surveys designed to identify interesting targets in a diverse set of galaxies for further study with JWST. These include the DUST in Nearby Galaxies with Spitzer (DUSTiNGS) program, which identified candidate dust-producing stars (especially AGB stars) in 50 dwarf galaxies out to 1.5 Mpc and the follow up HST and Spitzer programs that are classifying and monitoring the DUSTiNGS candidates. These surveys are intended to enable efficient targeting of a large sample of diverse sources with the JWST MIRI and NIRSpec specrographs for detailed analysis of the dust properties (see Bernard-Salas et al., presented at this conference). In particular, we target metal-poor dwarf galaxies that are representative of galaxies at high redshift to provide insight into the key role played by evolved stars in galaxy evolution at early epochs.
Talk