CfA OIR Division Lunch Talks
Thursday, May 22, 2008, 12:30 pm, Pratt Conference Room

Dust Production in Primordial Systems:
The View From the Spitzer Space Telescope

Dr. Greg Sloan (Cornell)

The Infrared Spectrograph on the Spitzer Space Telescope has the sensitivity to survey the production of dust by evolved stars in metal-poor galaxies in the Local Group. These spectra reveal several important dependencies of dust production with metallicity, and one lack of dependency. The amount of dust produced by carbon stars has little or no relation to the initial metallicity of the star. This result constrasts with evolved oxygen-rich stars, where the amount of silicate dust and its molecular precursors decreases with metallicity. In metal-poor systems, more stars will evolve into carbon stars, and consequently, a higher fraction of the dust injected into the interstellar medium will be carbon rich.