Related papers: Cu and Zn in the early Galaxy
We present the abundances of Li, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Zn, Sr, Y, Zr, and Ba in a wide metallicity range ($-2.8 \le$ [Fe/H] $\le -1.5$). Using the differential technique allowed us to obtain an unprecedented low…
The accurate O, Mg and Fe abundances derived in previous papers of this series from a homogenous reanalysis of high quality data for a large sample of stars are combined with stellar kinematics in order to discuss the history of star…
In this work we present and discuss the observations of the Mn abundances for 247 FGK dwarfs, located in the Galactic disc with metallicity -1<Fe/H]<+0.3. The observed stars belong to the substructures of the Galaxy thick and thin discs,…
Abundances of 18 elements are determined for the common proper-motion pair, HD134439 and HD134440, which shows high [Mn/Fe] and low [\alpha/Fe] ratios as compared to normal halo stars. Moreover, puzzling abundances are indicated from…
We report the first survey of chemical abundances in M and K dwarf stars using atomic absorption lines in high resolution spectra. We have measured Fe and Ti abundances in 35 M and K dwarf stars using equivalent widths measured from (lambda…
We performed a uniform and detailed analysis of 1112 high-resolution spectra of FGK dwarfs obtained with the HARPS spectrograph at the ESO 3.6 m telescope (La Silla, Chile). Most stars have effective temperatures 4700 K < Teff < 6300 K and…
Context. Elemental abundances are of prime importance to help us reconstruct the origin and evolution of stars and galaxies in our Universe. Sulfur abundances have not been as heavily studied as other elements, so some details regarding its…
High-resolution, high-signal-to-noise (<S/N> = 85) spectra have been obtained for five stars -- CD-24:17504, CD-38:245, CS 22172-002, CS 22885-096, and CS 22949-037 -- having [Fe/H] < -3.5 according to previous lower S/N material. LTE…
We present a new model atom of Zn I-II based on the most up-to-date photoionisation cross-sections, electron-impact excitation rates, and rate coefficients for the Zn I + H I and Zn II + H- collisions. The latter were calculated using the…
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,…
The atmospheric parameters and abundances of Mg, Si, Ca, and Ti have been determined for 20 stars using the Gaia DR2 parallaxes, high-resolution spectra, and the non-local thermodynamic equilibrium (non-LTE) line formation modeling. A…
Carbon and oxygen are key tracers of the Galactic chemical evolution; in particular, a reported upturn in [C/O] towards decreasing [O/H] in metal-poor halo stars could be a signature of nucleosynthesis by massive Population III stars. We…
Sulfur and zinc are chemically volatile elements, which play significant roles as depletion-free tracers in studying galactic chemical evolution. However, regarding red giants having evolved off the main sequence, reliable abundance…
In this work we present chemical abundances of heavy elements (Z$>$28) for a homogeneous sample of 1059 stars from HARPS planet search program. We also derive ages using parallaxes from Hipparcos and Gaia DR1 to compare the results. We…
In the framework of an ESO Large Programme high quality spectra of 70 very metal-poor dwarfs and giants were obtained with the VLT-UVES combination. This paper reports the detailed analyses of the 35 giants of the sample. At the exception…
We present chemical abundance analyses of sodium, iron-peak and neutron-capture elements for 97 kinematically selected thick disk, inner halo and outer halo stars with metallicities -3.3<[Fe/H]<-0.5. The main aim of this study is to examine…
Carbon and oxygen abundances in F and G main-sequence stars ranging in metallicity from [Fe/H] = -1.6 to +0.5 are determined from a non-LTE analysis of CI and OI atomic lines in high-resolution spectra. Both C and O are good tracers of…
We present an abundance analysis based on high resolution spectra of 8 stars selected to span the full range in metallicity in the Draco dwarf spheroidal galaxy. We find [Fe/H] for the sample stars ranges from -1.5 to -3.0 dex. Combining…
We present new measurements of the abundances of carbon and oxygen derived from high-excitation C I and O I absorption lines in metal-poor halo stars, with the aim of clarifying the main sources of these two elements in the early stages of…
We report the abundances of C, Na, Mg, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd, and Sm in 25 solar-type stars in the solar neighbourhood, and their correlations with ages, kinematics, and orbital parameters. The…