| Abstract [eng] |
Understanding the formation, structure and evolution of the Milky Way is one of the main open questions in modern astronomy. The Galaxy is made up of chemical elements originated from Big Bang to stellar nucleosynthesis. Among them, there are some that stand out for their special nucleosynthesis: they are the so-called neutron-capture elements. Although they are the majority among the elements, they only represent a small amount of the global composition of the Universe. However, it is in this small percentage where the keys of the evolution of the Galaxy are found. Among these keys are the chemical abundances. Based on 506 stars of the Solar neighbourhood observed at the Molėtai Astronomical Observatory and 62 open clusters from the Gaia ESO Survey, this thesis tried to answer some of the main questions in this field. Through its 6 chapters, the thesis deals with extremely important topics such as the temporal and spatial abundance gradients of neutron-capture elements in the Galactic thin and thick discs, as well as their application to calculate the ages of stars. Among its most significant results, the thesis provides new insights on s-processes indicators and the astrophysical origin of the r-process. For the first time a comprehensive analysis of the use of chemical clocks in the thick disc is made and the radial variations of calibrated chemical clocks are investigated in depth using a reliable sample of open clusters, indeed the largest used for this purpose. |
