Title: "Understanding the Effect of Metallicity on the Dust Production from Low and Intermediate Mass Stars"

Abstract: Understanding the effect of metallicity on the mass loss is of prime importance to determine the yields of low and intermediate mass stars in different galaxies and understanding the formation of dust in the early Universe. From Local Group Spitzer Infrared Spectrograph surveys, we showed that dust-production rates (DPRs) from oxygen-rich AGB stars are lower in more metal-poor environments, but for carbon stars, metallicity shows no strong influence. Substantial DPRs are observed for carbon stars with metallicities as low as ∼0.1 Zsun.  Those surveys have been performed using a highly biased sample, and our understanding of the mass-loss history from AGB stars is still mainly qualitative.

I will present new temporal photometric surveys aiming at defining an unbiased sample of AGB stars (in Globular Clusters such as M5 and M15 and Local Group galaxies such as Sextans and Sgr dSph). This will allow us to quantify the fraction of time stars spend in each stage of their main sequence evolution. Further IR and millimeter observations (with e.g. ALMA and the JWST) will enable us to measure the dust and gas production throughout their evolution and at different metallicity, and thus enable us to quantitatively measure how much does one generation of stars enrich and seed the interstellar medium (ISM) for the next generation.