Abstract
| Lucertini |
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| Sulfur as a tracer of the chemical evolution of the Milky Way |
| The alpha-elements are proof of the chemical enrichment delay due to Supernovae Type-II. When compared with iron, they can be used as cosmic clocks for placing constraints on both stellar nucleosynthesis and galaxy's formation history. Sulfur is the outcast alpha-element. Indeed, its analysis is often skipped in favor of the other alpha-elements, which are less complicated to measure. Among the alpha-elements, sulfur is the proxy for high-redshift systems. Its volatile nature allows us to directly compare sulfur abundances measured in local stars and gaseous phase in the far Universe, as extragalactic HII regions and Damped Ly-alpha systems (DLA). Since DLA have been proposed as progenitors of dwarf galaxies (i.e. the Milky Way building blocks), their study is relevant for the understanding of galaxies formation and evolution. However, the Sculptor dwarf spheroidal galaxy is the only extragalactic system for which sulfur abundances has been measured from stellar atmospheres. This talk presents the new results of my studies on the behavior of sulfur in the Milky Way major components. I will present abundances for 74 bulge stars, 21/30 thick/thin-disk stars, and 23 halo stars observed with FLAMES/UVES@VLT (Paranal, Chile). Exploiting sulfur as tracer of the chemical evolution of our Galaxy, I will provide clues on the Milky Way's formation and a reliable dataset to compare local and distant systems. |