Abundances of neutron-capture elements in stars of the galactic disk substructures

TL;DR

This study measures and analyzes the abundances of neutron-capture and iron-peak elements in 276 stars of the galactic disk, providing new chemical data and insights into their nucleosynthesis origins and galactic substructure membership.

Contribution

It presents new high-resolution spectroscopic measurements of neutron-capture elements in a large stellar sample, with detailed chemical analysis and galactic population classification.

Findings

Most stars' neutron-capture element abundances were measured for the first time.

Stars are classified into galactic substructures based on their kinematics.

The data shed light on nucleosynthesis contributions to galactic chemical evolution.

Abstract

The aim of this work is to present and discuss the observations of the iron peak (Fe, Ni) and neutron-capture element (Y, Zr, Ba, La, Ce, Nd, Sm, and Eu) abundances for 276 FGK dwarfs, located in the galactic disk with metallicity -1 < [Fe/H] < +0.3. Atmospheric parameters and chemical composition of the studied stars were determined from an high resolution, high signal-to-noise echelle spectra obtained with the echelle spectrograph ELODIE at the Observatoire de Haute-Provence (France). Effective temperatures were estimated by the line depth ratio method and from the H_{\alpha} line-wing fitting. Surface gravities (log g) were determined by parallaxes and the ionization balance of iron. Abundance determinations were carried out using the LTE approach, taking the hyperfine structure for Eu into account, and the abundance of Ba was computed under the NLTE approximation. We are able to assign most of the stars in our sample to the substructures of the Galaxy thick disk, thin disk, or Hercules stream according to their kinematics. The classification of 27 stars is uncertain. For most of the stars in the sample, the abundances of neutron-capture elements have not been measured earlier. For all of them, we provide the chemical composition and discuss the contribution from different nucleosynthesis processes.