SAC Seminar - Sergio Cristallo: Asymptotic Giant Branch stars: what we know and what we wish to know
Oplysninger om arrangementet
Asymptotic Giant Branch (AGB) stars are among the most important polluters of the interstellar medium. Their rich nucleosynthesis occurs in a wide range of temperatures and densities. Atoms are produced in their interiors, via charged particle reactions and thanks to the slow neutron capture process (the s-process). In their atmospheres, when the temperature drops below 5000 K, oxygen and carbon bearing molecules form, depending on the local C/O ratio. Further away from the central star, in their cool and expanded circumstellar envelopes, molecules cluster, leading to the formation of dust grains. I will present our stellar models (included in the FRUITY database), by describing how we model physical phenomena (as convection and rotation) as well as the ongoing nucleosynthesis. Moreover, I will introduce a new project aimed at modelling molecule and dust formation in the circumstellar envelopes of these objects, by highlighting pro and cons of our approach to the problem.