相关论文: Enrichment of the Galactic disc with neutron-captu…
Photospheric abundances are presented for 27 elements from carbon to europium in 181 F-G dwarfs from a differential LTE analysis of high-resolution and high signal-to-noise spectra. Stellar $T_{\rm eff}$ were adopted from an infrared flux…
We present new observational data for the heavy elements molybdenum (Mo, Z = 42) and ruthenium (Ru, Z = 44) in F-, G-, and K-stars belonging to different substructures of the Milky Way. The range of metallicity covered is --1.0 $<$ [Fe/H]…
The enrichment history of heavy neutron-capture elements in the Milky Way disc provides fundamental information about the chemical evolution of our Galaxy and about the stellar sources that made those elements. In this work we give new…
The chemical evolution of neutron capture elements in the Milky Way disc is still a matter of debate. We aim to understand the chemical evolution of r-process elements in Milky Way disc. We focus on three pure r-process elements Eu, Gd, and…
Knowledge of abundance ratios as functions of metallicity can lead to insights on the origin and evolution of our Galaxy and its stellar populations. We aim to trace the chemical evolution of the neutron-capture elements Sr, Zr, La, Ce, Nd,…
The aim of this work is to determine abundances of neutron-capture elements for thin- and thick-disc F, G, and K stars in several sky fields near the north ecliptic pole and to compare the results with the Galactic chemical evolution…
The actinides, including thorium (Th), are the heaviest observable elements synthesized in the universe, holding clues to the extremes of the astrophysical and nuclear conditions of $r$-process sites. We present Th abundances based on…
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 <…
We have investigated the thorium (Th) abundance in a sample of 53 thin disc solar twins covering a wide range of ages. These data provide constrains on the mantle energy budget of terrestrial planets that can be formed over the evolution of…
To better characterize the abundance patterns produced by the r-process, we have derived new abundances or upper limits for the heavy elements zinc (Zn), yttrium (Y), lanthanum (La), europium (Eu), and lead (Pb). Our sample of 161…
We have studied 23 long-lived G dwarfs that belong to the thin disk and thick disk stellar populations. Abundances have been derived for 24 elements: O, Na, Mg, Al, Si, Ca, Ti, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd,…
We present new abundance determinations of neutron-capture elements Ge, Zr, Os, Ir, and Pt in a sample of 11 metal-poor (-3.1 <= [Fe/H] <= -1.6) Galactic halo giant stars, based on Hubble Space Telescope UV and Keck I optical…
We present new accurate abundances for five neutron-capture (Y, La, Ce, Nd, Eu) elements in 73 classical Cepheids located across the Galactic thin disk. Individual abundances are based on high spectral resolution (R ~ 38,000) and high…
From a detailed elemental abundance analysis of 102 F and G dwarf stars we present abundance trends in the Galactic thin and thick disks for 14 elements (O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Zn, Y, Ba, and Eu). Stellar parameters and…
HD 140283 is a nearby (V=7.7) subgiant metal-poor star, extensively analysed in the literature. Although many spectra have been obtained for this star, none showed a signal-to-noise (S/N) ratio high enough to enable a very accurate…
We present a strictly line-by-line differential analysis of a moderately $r$-process-enhanced star ($r$-I: HD~107752) with respect to a strongly $r$-process-enhanced star ($r$-II: CS~31082-0001) to investigate the possible common origin of…
Based on high quality spectral data (spectral resolution R>60000) within the wavelength range of 3550-5000 AA we determined main parameters (effective temperature, surface gravity, microturbulent velocity, and chemical element abundances…
To understand the formation and evolution of the different stellar populations within our Galaxy it is essential to combine detailed kinematical and chemical information for large samples of stars. We derive chemical abundances of Cu, Zn,…
We present a survey of lithium abundances in 185 main- sequence field stars with Teff between 5600 and 6600 K and [Fe/H] from -1.4 to +0.2 based on high-resolution spectra of 130 stars and a reanalysis of data from Lambert et al. (1991).…
A renewed interest about the origin of \emph{r}-process elements has been stimulated by the multi-messenger observation of the gravitational event GW170817, with the detection of both gravitational waves and electromagnetic waves…