I'm currently involved in several projects, large and small, which can be organized into the following themes:
As a post-doc at NASA Ames. I collaborated with Jesse Bregman on a study of infrared spectral emission from organic molecules in space. Using a combination of spectral and spatial data, we made several important discoveries which shed light on the composition of these molecules. I've returned to this project with new data from the Spitzer Space Telescope.
By analyzing the infrared spectra from large numbers of dust shells formed around dying stars, Steve Price and I found several important correlations between the properties of the dust and the properties of the star. These findings provide clues to the mass-loss process that leads to the death of stars. I began this project as a post-doc at Phillips Lab.
As a research fellow at Cornell, I have continued my study of mass loss and dust production with the Spitzer Space Telescope, which is so sensitive, we can study evolved stars in the closest galaxies to our own. These galaxies often have abundances very different from the Milky Way and much closer to the primordial abundances in the early Universe, when virtually nothing existed except hydrogen and helium. Spitzer gives us the chance to compare evolved stars in these other galaxies to the samples I have studied previously. The differences we have uncovered provide important clues for how dying stars enrich space with heavy elements, and how this enrichment process has varied as these heavy elements have grown more abundant with time.
The atmospheres of cool stars and brown dwarfs contain molecules which can't form in hotter stars, and these dominate the infrared spectra. I was a co-author on the first papers describing the spectrum from a brown dwarf, and now that the Spitzer Space Telescope has been observing many brown dwarfs, I find myself involved in studying these objects once again. Red giants also have molecular bands in their spectra, and this is important because these stars are often used as calibrators. I will try and add a link to more details about this research shortly.
My International Research Fellowship in Australia focused on the physical structure of dust shells around dying stars. Craig Smith and I obtained images of several evolved and extended stars.
HomeLast modified 20 December, 2007. © Gregory C. Sloan.