English
Related papers

Related papers: Galactic abundance gradients from Cepheids: alpha …

200 papers

We derived the barium atmospheric abundances for a large sample of Cepheids, comprising 270 stars. The sample covers a large range of galactocentric distances, from about 4 to 15 kpc, so that it is appropriated to investigate the existence…

Astrophysics of Galaxies · Physics 2015-06-11 S. M. Andrievsky , J. R. D. Lepine , S. A. Korotin , R. E. Luck , V. V. Kovtyukh , W. J. Maciel

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 Open Cluster Chemical Abundances and Mapping (OCCAM) survey aims to constrain key Galactic dynamical and chemical evolution parameters by the construction of a large, comprehensive, uniform, infrared-based spectroscopic data set of…

Recent observations demonstrate that the thin and thick disks of the Galaxy have different chemical abundance trends and evolution timescales. The relative abundances of $\alpha$-elements in the thick Galactic disk are increased relative to…

Astrophysics · Physics 2009-11-11 T. V. Nykytyuk , T. V. Mishenina

The temporal behaviour of the radial abundance gradients has important consequences on models for the chemical evolution of the Galaxy. We present a comparison of the time variation of the abundance gradients in the Milky Way disk as…

Astrophysics · Physics 2007-05-23 W. J. Maciel , R. D. D. Costa , P. A. L. Ferreira

The observed radial and vertical metallicity distribution of old stars in the Milky Way disk provides a powerful constraint on the chemical enrichment and dynamical history of the disk. We present the radial metallicity gradient,…

We present a chemical abundance distribution study in 14 $\alpha$, odd-Z, even-Z, light, and Fe-peak elements of approximately 3200 intermediate metallicity giant stars from the APOGEE survey. The main aim of our analysis is to explore the…

Astrophysics of Galaxies · Physics 2016-03-02 Keith Hawkins , Paula Jofre , Thomas Masseron , Gerry Gilmore

Previous nonlinear fundamental pulsation models for classical Cepheids with metal content Z <= 0.02 are implemented with new computations at super-solar metallicity (Z=0.03, 0.04) and selected choices of the helium-to-metal enrichment ratio…

Astrophysics · Physics 2009-11-07 G. Fiorentino , F. Caputo , M. Marconi , I. Musella

Chemical cartography of the Galactic disk provides insights to its structure and assembly history over cosmic time. In this work, we use chemical cartography to explore chemical gradients and azimuthal substructure in the Milky Way disk…

The spatial distribution of chemical elements in the Galactic disk provides key constraints on models of galaxy evolution. However, studies using planetary nebulae (PNe) as tracers have been historically limited by large uncertainties in…

[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…

Astrophysics · Physics 2009-11-13 Bacham E. Reddy , David L. Lambert , Carlos Allende Prieto

Chemical abundances are an essential tool in untangling the Milky Way's enrichment history. However, the evolution of the interstellar medium abundance gradient with cosmic time is lost as a result of radial mixing processes. For the first…

We provided accurate estimates of distances, radii and iron abundances for four metal-rich Cepheids, namely V340 Ara, UZ Sct, AV Sgr and VY Sgr. The main aim of this investigation is to constrain their pulsation properties and their…

Solar and Stellar Astrophysics · Physics 2015-05-18 S. Pedicelli , B. Lemasle , M. Groenewegen , M. Romaniello , G. Bono , C. D. Laney , P. Francois , R. Buonanno , F. Caputo , J. Lub , J. W. Pel , F. Primas , J. Pritchard

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Daniel Thomas , Jonas Johansson , Claudia Maraston

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…

Astrophysics of Galaxies · Physics 2015-06-16 Miho N. Ishigaki , Wako Aoki , Masashi Chiba

Abundances of alpha-elements such as Ca and Mg in disk and halo stars are usually derived from equivalent widths lines measured on high resolution spectra, and assuming Local Thermodynamic Equilibrium (LTE) . In this paper, we present…

Astrophysics · Physics 2009-10-31 T. Idiart , F. Thevenin

Although there have been numerous studies of chemical abundances in the Galactic bulge, the central two degrees have been relatively unexplored due to the heavy and variable interstellar extinction, extreme stellar crowding, and the…

Astrophysics of Galaxies · Physics 2019-07-17 M. Schultheis , R. M. Rich , L. Origlia , N. Ryde , G. Nandakumar , B. Thorsbro , N. Neumayer

Context: The chemical abundances of alpha-elements in Galactic Centre (GC) supergiants provide key insights into the chemical enrichment and star formation history of the Milky Way's Nuclear Star Cluster. Previous studies have reported…

Astrophysics of Galaxies · Physics 2026-01-14 B. Thorsbro , S. Khalidy , R. M. Rich , M. Schultheis , D. Taniguchi , A. M. Amarsi , G. Kordopatis , G. Nandakumar , S. Nishiyama , N. Ryde

We have undertaken the study of the elemental abundances and kinematic properties of a metal-poor sample of candidate thick-disk stars selected from the RAVE spectroscopic survey of bright stars to differentiate among the present scenarios…

‹ Prev 1 3 4 5 6 7 10 Next ›