Related papers: Thin and Thick Galactic Disks
Growing interests in the chemical feature of r-process elements among nearby disk stars represented by the [Eu/Fe] vs. [Fe/H] diagram have sprouted since it can assess the origin of r-process elements through the comparison with theoretical…
In this paper we present a new chemical evolution model for the Galaxy which assumes two main infall episodes for the formation of halo-thick disk and thin disk, respectively. We do not try to take into account explicitly the evolution of…
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…
Using modern published data on velocities and spectroscopic definitions of chemical elements in stellar objects of the Galaxy, we investigated the relationship of chemical composition with the kinematics of different populations. The paper…
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…
Radial velocity surveys such as the Radial Velocity Experiment (RAVE) provide us with measurements of hundreds of thousands of nearby stars most of which belong to the Galactic thin, thick disk or halo. Ideally, to study the Galactic disks…
Exoplanet demographic surveys have revealed that close-in (${\lesssim}$1 au) small planets orbiting stars in the Milky Way's thick disk are ${\sim}50\%$ less abundant than those orbiting stars in the Galactic thin disk. One key difference…
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 discuss the age of the stellar disks in the solar neighbourhood. After reviewing the various methods for age dating we discuss current estimates of the age of both the thin and the thick disk. We present preliminary results for…
The analysis of the kinematics of solar neighbourhood stars shows that the low and high metallicity tails of the thin disc are populated by objects which orbital properties suggest an origin in the outer and inner galactic disc,…
Abundances of C, O, and Fe are determined for F and G main-sequence stars in the solar neighborhood in order to study trends and systematic differences in the C/Fe, O/Fe, and C/O ratios for stellar populations. Carbon abundances are…
Gas-rich dwarf and disk galaxies overlap in numerous physical quantities that make their classification subjective. We report the discovery of a separation between dwarfs and disks into two unique sequences in the mass (luminosity) versus…
The evolution of C and O abundances in the Milky Way can impose strong constraints on stellar nucleosynthesis and help understanding the formation and evolution of our Galaxy. The aim is to review the measured C and O abundances in the disk…
We investigate, using the Gaia-ESO Survey internal Data-Release 2, the properties of the double sequence of the Milky Way discs (defined chemically as the high-alpha and low-alpha populations), and discuss their compatibility with discs…
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…
(Abridged) The abundance ratios between key elements such as iron and alpha-process elements carry a wealth of information on the star formation history (SFH) of galaxies. So far, simple chemical evolution models have linked [alpha/Fe] with…
Atmospheric parameters and oxygen abundances of 825 nearby FGK stars are derived using high-quality spectra and a non-LTE analysis of the 777 nm O I triplet lines. We assign a kinematic probability for the stars to be thin-disk (P1),…
Thick disks are a prevalent feature observed in numerous disk galaxies including our own Milky Way. Their significance has been reported to vary widely, ranging from a few to 100% of the disk mass, depending on the galaxy and the…
Some low surface brightness galaxies are known to have extremely thin stellar disks with the vertical to planar axes ratio 0.1 or less, often referred to as superthin disks. Although their existence is known for over three decades, the…
We study the evolution of nitrogen in the Galactic halo, thick disc, thin disc and bulge by comparing detailed chemical evolution models with recent observations. The models used in this work have already been constrained to explain the…