| Abstract [eng] |
New astronomical data is constantly being released. New Gaia data releases have already provided us with information for almost 2 billion stars and more new data will reach us in upcoming years. On the other hand, spectroscopic investigations are available for much smaller samples. Thus, spectroscopic investigations are needed in order to gain better insight into the evolution of stars and the Galaxy. A chemical element group beyond iron, the so-called neutron-capture chemical elements, are even less studied. As this group of elements is very wide and elements are made in very diverse conditions, these elements can provide new perspectives to better understand the Galaxy. However, theoretical modeling and spectroscopic investigations of these elements in many cases do not come to the same conclusions. In this study, 113 stars in the Solar neighbourhood, 94 of which belong to the thin and 19 – to the thick disc, were spectroscopically studied and abundances of 8 neutron capture chemical elements – yttrium, zirconium, barium, lanthanum, cerium, praseodymium, neodymium and europium – were determined. In addition, ages and kinematical parameters were derived as well. Comparing abundances results of this work with models from Prantzos ir kt. (2018); Kobayashi ir kt. (2020); Van der Swaelmen ir kt. (2023), it was concluded that elements belonging to the first 𝑠-process peak, Y and Zr, have 𝑟-process origin of ∼22% and ∼44%, respectively with the remaining part produced from 𝑠-process in asymptotic giant branch stars. A large 𝑠-process contribution of ∼89%, ∼80% and ∼85% is confirmed for Ba, La and Ce, elements from the second 𝑠-process peak. Higher 𝑟-process contribution than suggested in literature (38% and 46%) is also proposed for Nd and Pr. Especially Pr shows europium-like behaviour. Results from this work support the models which suggest that the Eu origins primarily from magneto-rotational supernova. In the thin disc, negative tendencies with age are found for all 𝑠-process dominated elements, especially for barium, while 𝑟-process dominated europium shows a positive trend. The thick disc star sample is rather small, however for all investigated elements positive gradients with age can be inferred. |
