Chemical composition of giants from two moving groups

TL;DR

This study analyzes the chemical compositions of 19 K-type giants from two moving groups, revealing their elemental abundance patterns and suggesting diverse chemical origins before their current kinematic association.

Contribution

It provides detailed elemental abundances for giants in two moving groups, highlighting differences in chemical evolution and supporting the dynamical resonant theory.

Findings

Most elemental abundances align with previous studies.

Na, Al, and Ba are significantly affected by stellar evolution.

Distinct [Mg/Ba] ratios indicate different chemical histories.

Abstract

We present stellar parameters of 19 K-type giants and their abundances of 13 chemical elements (Al, Ba, Ca, Fe, K, Mg, Mn, Na, Ni, Sc, Si, Ti and V), selected from two moving groups, covering the metallicity range of -0.6 < [Fe/H] < 0.2, based on high resolution spectra. Most elemental abundances show similar trends with previous studies except for Al, Na and Ba, which are affected by evolution seriously. The abundance ratios of [Na/Mg] increase smoothly with higher [Mg/H] and [Al/Mg] decrease slightly with increasing [Mg/H]. [Mg/Ba] show distinction between these two moving groups which is mainly induced by chemical evolution and partly by kinematic effects. The inhomogeneous metallicity of each star from the moving groups demonstrate that these stars have different chemical origins before they were kinematically aggregated and favor the dynamical resonant theory.