Units

Astronomy and Astrophysics Institute

The IAA is involved in theoretical and observational research activities in various fields of astrophysics. These concern in particular the synthesis of atomic nuclei, the chemical and isotopic composition of the solar system and of stars from our Galaxy, the structure and evolution of low- and intermediate-mass stars including diferent mixing processes as well as the modelling of binary systems and of stellar hydrodynamic phenomena of the detonation type. The modeling of the above phenomena is compared with observed quantities, like the chemical composition of stars from various classes. The chemical composition is derived using the best tools, both observational (telescopes and spectrographs from the European Southern Observatory, or from our own high-resolution spectrograph HERMES) and theoretical (model atmospheres, atomic and molecular data). Similarly, nucleosynthesis predictions require many nuclear data which are collected and evaluated, or generated in large-scale theoretical calculations. They are used to generate extended nuclear reaction networks which are made available to the astrophysical community. Besides these research topics where I.A.A. has long been recognized has an international centre of excellence, I.A.A. nowadays contributes substantially to the preparation of the E.S.A. Gaia mission. Astrometry and galactic dynamics are therefore two new active research fields at I.A.A.

Projetcs

Modelling of the evolution and nucleosynthesis of stars.

Study of the structure and evolution of low and intermediate mass from the T-Tauri to the Asymptotic Red Giant Branch and white darf evolutionary stage : construction of efficient computer codes, improvement of the physics of stellar interiors by taking into account the transport of angular momentun and chemicals (by rotation, overshooting and gravity waves) and of the URCA process. Confrontation between calculated and observed surface compositions. Hydrodynamical simulations of the propagation of shock waves, detonation t the surface of white dwarfs and neutron stars. Determination of yields and implicaitions to the galactical chemical evolution. Study of the nucleosynthesis in advanced stellar evolutionary phases of massive stars.

Nuclear data for astrophysics : nucleosynthesis processes

Theoretical study of various nuclear quantities of importance for stellar evolution models and for the nucleosynthesis: nuclear reaction rates, weak interaction fission, nuclear masses and level densities. Study of the non-explosive and explosive of stellar nucleosynthesis aiming to understand the chemical and isotopic composition of the solar system, of stars and galaxies.