Related papers: The Abundance Pattern of $\alpha$ elements in the …
The Triangulum--Andromeda (TriAnd) overdensity is a distant structure of the Milky Way located in the second Galactic quadrant well below the Galactic plane. Since its discovery, its nature has been under discussion, whether it could be old…
The nature of the Triangulum-Andromeda (TriAnd) system has been debated since the discovery of this distant, low-latitude Milky Way (MW) overdensity more than a decade ago. Explanations for its origin are either as a halo substructure from…
We present a chemodynamical study of the Triangulum-Andromeda overdensity (TriAnd) employing a sample of 31 candidate stars observed with the GRACES high-resolution ($R$=40,000) spectrograph at the Gemini North (8.1 m) telescope. TriAnd is…
We undertake the first high resolution spectroscopic study of the Triangulum-Andromeda (TriAnd) star cloud --- an extended, mid-latitude Milky Way halo substructure about 20 kpc away in the second Galactic quadrant --- through six M giant…
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…
For the first time, we present an extensive study of stars with individual non-local thermodynamic equilibrium (NLTE) abundances for 17 chemical elements from Li to Eu in a sample of stars uniformly distributed over the $-2.62 \le$ [Fe/H]…
Many nucleosynthetic channels create the elements, but two-parameter models characterized by $\alpha$ and Fe nonetheless predict stellar abundances in the Galactic disk to accuracies of 0.02 to 0.05 dex for most measured elements, near the…
We present the results of our investigation of three samples kinematically representative of the thin and thick disks and the Hercules stream using the catalogue of Soubiran & Girard (2005). We have observed abundance trends and age…
Based on a simple, but fairly successful, model of the chemical evolution of the Milky Way disk, we study the evolution of the abundances of the elements He, C, N, O, Ne, Mg, Al, Si, S, Ar and Fe. We use metallicity dependent yields for…
We model the abundance gradients in the disk of the Milky Way for several chemical elements (O, Mg, Si, S, Ca, Sc, Ti, Co, V, Fe, Ni, Zn, Cu, Mn, Cr, Ba, La and Eu), and compare our results with the most recent and homogeneous observational…
Chemical abundances of stars in the Milky Way disk are empirical tracers of its enrichment history. However, they capture joint-information that is valuable to disentangle. In this work, we seek to quantify how individual abundances evolve…
We explore the Triangulum-Andromeda (TriAnd) overdensity in the SPLASH (Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo) and SEGUE (the Sloan Extension for Galactic Understanding and Exploration) spectroscopic surveys.…
We use our new, flux-calibrated stellar population model of absorption-line indices to derive ages, metallicities, and various element abundance ratios from integrated light spectroscopy of galactic globular clusters. The ages agree well…
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 discuss oxygen and iron abundance patterns in K and M red-giant members of the Galactic bulge and in the young and massive M-type stars inhabiting the very center of the Milky Way. The abundance results from the different bulge studies…
We present a detailed chemical abundance study of evolved stars in 10 open clusters based on Hydra multi-object echelle spectra obtained with the WIYN 3.5m telescope. From an analysis of both equivalent widths and spectrum synthesis,…
[Abridged abstract] We have performed an abundance analysis for 176 F- and G- dwarfs of the Galactic thick disk component. Using accurate radial velocities combined with $Hipparcos$ astrometry, kinematics (U, V, and W) and Galactic orbital…
We employ the first two years of data from the near-infrared, high-resolution SDSS-III/APOGEE spectroscopic survey to investigate the distribution of metallicity and alpha-element abundances of stars over a large part of the Milky Way disk.…
Using multi-element abundances from the SDSS APOGEE survey, we investigate the origin of abundance variations in Milky Way (MW) disk stars on the "high-$\alpha$ plateau," with $-0.5\leq\rm{[Mg/H]}\leq-0.1$ and…
Recent theoretical yields and chemical evolution models demonstrate that intermediate-mass AGB stars cannot reproduce the observed abundance distributions of O, Na, Mg, and Al. As a further observational test of this finding, we present…