相关论文: Chemical compositions of semi-regular variable red…
Measurements are presented and analyzed of the strength of the Ca II triplet lines in red giants in Galactic globular and open clusters, and in a sample of red giants in the LMC disk that have significantly different [Ca/Fe] abundance…
This paper presents a study of the chemical compositions in cool gas around a sample of 27 intermediate-redshift galaxies. The sample comprises 13 massive quiescent galaxies at z=0.40-0.73 probed by QSO sightlines at projected distances…
We present detailed chemical compositions of 10 red giant star members of the Galactic (open) cluster NGC 752, derived from high-resolution (R $\approx$ 60,000), high signal-to-noise ($S/N$ $\geq$ 140) spectra. We confirmed cluster…
Context: Homogeneous investigations of red giant stars in open clusters contribute to studies of internal evolutionary mixing processes inside stars, which are reflected in abundances of mixing-sensitive chemical elements like carbon,…
Chemical abundances of 26 metal-poor dwarfs and giants are determined from high-resolution and high signal-to-noise ratio spectra obtained with Subaru/HDS. The sample is selected so that most of the objects have outer-halo kinematics.…
Stellar parameters of 25 planet-hosting stars and abundances of Li, C, O, Na, Mg, Al, S, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni, Zn, Y, Zr, Ba, Ce, Pr, Nd, Sm and Eu, were studied based on homogeneous high resolution spectra and uniform…
The abundances of iron and oxygen are homogeneously determined in a sample of 523 nearby (d<150 pc) FGK disk and halo stars with metallicities in the range -1.5<[Fe/H]<0.5. The oxygen abundances were inferred from a restricted non-LTE…
The study of symbiotic systems is of considerable importance in our understanding of binary system stellar evolution in systems where mass loss or transfer takes place. Elemental abundances are of special significance since they can be used…
Accurate atmospheric parameters and chemical composition of planet-hosting stars are crucial for characterising exoplanets and understanding their formation and evolution. Our objective is to uniformly determine the atmospheric parameters…
We measure chemical abundance ratios and radial velocities in four massive (i.e., young) [alpha/Fe]-rich red giant stars using high-resolution high-S/N spectra from ESPaDOnS fed by Gemini-GRACES. Our differential analysis ensures that our…
Determinations of the chemical composition of red giants in a large sample of open clusters show that the abundances of the heavy elements La, Ce, Nd and Sm but not so obviously Y and Eu vary from one cluster to another across a sample all…
We use abundances of Ca, O, Na, Al from high resolution UVES spectra of 200 red giants in 17 globular clusters (GCs) to investigate the correlation found by Lee et al. (2009) between chemical enrichment from SN II and star-to-star…
We present fundamental stellar parameters and chemical abundances for a sample of 86 evolved stars with planets and for a control sample of 137 stars without planets. The analysis was based on both high S/N and resolution echelle spectra.…
A non-LTE analysis of K I resonance lines at 7664.91 and 7698.97 A was carried out for 15 red giants belonging to three globular clusters of different metallicity (M 4, M 13, and M 15) along with two reference early-K giants (rho Boo and…
We present the first fluorine measurements in 12 normal giants belonging to the Galactic thin and thick disks using spectra obtained with the Phoenix infrared spectrometer on the 2.1m telescope at Kitt Peak. Abundances are determined from…
A metallicity, chemical composition, and kinematic survey has been conducted for a sample of 340 candidate field red horizontal branch stars. High resolution, high signal-to-noise spectra were gathered with the McDonald Observatory 2.7m…
Aims. The aim of this work is the study of abundances of the heavy elements Ba, La, Ce, Nd, and Eu in 56 bulge giants (red giant branch and red clump) with metallicities ranging from -1.3 dex to 0.5 dex. Methods. We obtained high-resolution…
Capella is a spectroscopic binary consisting of two G-type giants, where the primary (G8III) is a normal red-clump giant while the secondary (G0III) is a chromospherically-active fast rotator showing considerable overabundance of Li as…
Recent spectroscopic explorations of large Galactic stellar samples stars have revealed the existence of red giants with [$\alpha$/Fe] ratios that are anomalously high, given their relatively young ages. We revisit the GALAH DR3 survey to…
We present aluminium, magnesium, and silicon abundances in the metal-poor globular cluster NGC 6752 for a sample of more than 130 red giants with homogeneous oxygen and sodium abundances. We find that [Al/Fe] shows a spread of about 1.4 dex…