Related papers: O and Fe abundance correlations and distributions …
We present a study of the chemical abundances of Solar neighbourhood stars associated to dynamical structures in the Milky Way's (thick) disk. These stars were identified as overdensity in the eccentricity range 0.3< ecc < 0.5 in the…
The damped Lyman alpha systems seen in the spectra of high redshift QSOs offer the means to determine element abundances in galaxies observed while still at an early stage of evolution. Such measurements, which have only recently come…
Correlations between stellar kinematics and chemical abundances are fossil evidence for evolutionary connections between Galactic structural components. Extensive stellar surveys show that the only tolerably clear distinction between…
(Abbreviated) We present a detailed analysis of the space motions of 1203 solar-neighborhood stars with metal abundances [Fe/H] <= -0.6, on the basis of a recently revised and supplemented catalog of metal-poor stars selected without…
We present the iron abundance and abundance ratios for 18 elements with respect to Fe in a sample of stars with a wide range in luminosity from luminous giants to stars near the turnoff in the globular cluster M5. The analyzed spectra,…
Galactic and extragalactic abundance studies of H II regions, planetary nebulae, and supernova remnants are compiled and their implications briefly reviewed. Galaxy global metallicity appears to be related directly to total mass and…
Understanding the evolution of the N/O ratio in the interstellar medium (ISM) of galaxies is essential if we are to complete our picture of the chemical evolution of galaxies at high redshift, since most observational calibrations of O/H…
Non-LTE analysis (LTE is local thermodynamic equilibrium) of the oxygen abundances for 51 Galactic A-, F- and G-type supergiants and bright giants is performed. In contrast with carbon and nitrogen, oxygen does not show any significant…
We study the chemical evolution and formation of the Galactic halo through the analysis of its stellar metallicity distribution function and some key elemental abundance patterns. Starting from the two-infall model for the Galaxy, which…
Using two alternative [O/H]-[Fe/H] dependences, the empirical oxygen abundance distribution (EGD) is deduced from two different samples of old objects, available in the literature. Under the assumption that each distribution (with the…
It is well established that the chemical structure of the Milky Way exhibits a bimodality with respect to the $\alpha$-enhancement of stars at a given [Fe/H]. This has been studied largely based on a bulk $\alpha$ abundance, computed as a…
We present deep spectrophotometry of 18 HII regions in the nearby massive spiral galaxies M101 and M31. We have obtained direct determinations of electron temperature in all the nebulae. We detect the CII 4267 line in several HII regions,…
We report new measurements of carbon and oxygen abundances in 34 F and G dwarf and subgiant stars belonging to the halo population and spanning a range of metallicity from [Fe/H] = -0.7 to -3.2 . The survey is based on observations of four…
We study the oxygen abundance profiles of the gas-phase components in hydrodynamical simulations of pre-prepared disc galaxies including major mergers, close encounters and isolated configurations. We analyse the evolution of the slope of…
We present oxygen abundances for 72 F and G dwarf stars in the solar neighbourhood. Using the kinematics of the stars we divide them into two sub-samples with space velocities that are typical for the thick and thin disks, respectively. The…
We study the origin of the stellar $\alpha$-element-to-iron abundance ratio, $[\alpha/\mathrm{Fe}]_{\ast}$, of present-day central galaxies, using cosmological, hydrodynamical simulations from the Evolution and Assembly of GaLaxies and…
The abundance of beryllium in the oldest, most metal-poor stars acts as a probe of early star formation and Galactic chemical evolution. We have analyzed high-resolution, high signal-to-noise Keck/HIRES spectra of 24 stars with [Fe/H] from…
We have re-evaluated empirical expressions for the abundance determination of N, O, Ne, S, Cl, Ar and Fe taking into account the latest atomic data and constructing an appropriate grid of photoionization models with state-of-the art model…
The relationship between abundances and orbital parameters for 235 F- and G-type intermediate- and low- mass stars in the Galaxy is analyzed. We found that there are abundance gradients in the thin disk in both radial and vertical…
We conducted an investigation on the chemical abundances of 4,316 stars in the red giant branch (RGB) phase from the recently released APO-K2 catalogue. Our aim was to characterize the abundance trends of the single elements with…