LABORATORI NAZIONALI DI FRASCATI
Speaker: Silvia Tosi (LNF INFN) The life of the stars is characterized by several processes able to change their chemical composition and structure. The impact and the way with which these mechanisms are active depends on several factors and the most relevant is the mass with which these stars were formed. The present talk will retrace the evolution of the low- and intermediate-mass stars (LIMS), characterized by masses between 1 and 8 solar masses. During their evolution, the LIMS will cross the asymptotic giant branch (AGB) phase, which is characterized by nucleosynthesis and physical phenomena able to deeply alter their surface chemistry. It is well known that during this stage, the circumstellar envelope is an ideal environment for the formation of dust, whose mineralogy reflects the evolutionary history that the star has undergone. Since the LIMS are major sources for the chemical enrichment of the interstellar medium, it is fundamental to characterize the dust formed and to understand the reprocessed elements that will contaminate the host galaxies. In addition, in most cases, the surface chemical composition of the star remains relatively stable during the transition from the AGB to the planetary nebula phase, and for this reason, it is possible to use the stages that occur after the AGB one to retrieve information on the processes that were active during the AGB evolution (e.g. nucleosynthesis, mass-loss, dust production). This talk will show the potentialities of the studies focused on the dust, connecting the mineralogy of the dust observed with the past evolutionary history. To achieve this goal, it will be used observational data (e.g. spectra, photometric data and abundances) to interpret the spectral energy distribution of post-AGB and Planetary nebulae that likely evolved as single stars, taken from the Magellanic Clouds and in the Milky Way.

DATA: 26-02-2025