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相关论文: Elemental Abundance Survey of The Galactic Thick D…

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Most, if not all, disk galaxies have a thin (classical) disk and a thick disk. In most models thick disks are thought to be a necessary consequence of the disk formation and/or evolution of the galaxy. We present the results of a study of…

Following the recent abundance measurements of Mg, Al, Ca, Fe, and Ni in the black hole X-ray binary XTE J1118+480 using medium-resolution Keck II/ESI spectra of the secondary star (Gonz\'alez Hern\'andez et al. 2006), we perform a detailed…

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…

星系天体物理 · 物理学 2023-02-08 Bridget Ratcliffe , Melissa Ness

Abundances for Fe, O, and the alpha-elements (Mg, Si, Ca, and Ti) have been derived from high resolution spectra of a sample of about one hundred dwarfs with high precision parallaxes measured by HIPPARCOS. The stars have metal abundances…

天体物理学 · 物理学 2007-05-23 R. G. Gratton , E. Carretta , G. Clementini , C. Sneden

The aim of this paper is to provide the fundamental parameters and abundances for a large sample of local clump giants with a high accuracy. The selection of clump stars for the sample group was made applying a color - absolute magnitude…

The present sample of nearby bulgelike dwarf stars has kinematics and metallicities characteristic of a probable inner disk or bulge origin. Ages derived by using isochrones give 10-11 Gyr for these stars and metallicities are in the range…

天体物理学 · 物理学 2009-11-07 Luciana Pompeia , Beatriz Barbuy , Michel Grenon

We present chemical abundances for O, Na, Mg, Al, Si, Ca, Ti and Fe in eight red giants and one turnoff star in the metal rich globular cluster 47 Tuc, based on spectroscopy with the MIKE high resolution spectrograph on the Magellan 6.5-m…

天体物理学 · 物理学 2009-11-13 Andreas Koch , Andrew McWilliam

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…

天体物理学 · 物理学 2009-10-31 T. Idiart , F. Thevenin

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…

太阳与恒星天体物理 · 物理学 2017-12-06 Henrique Reggiani , Jorge Meléndez , Chiaki Kobayashi , Amanda Karakas , Vinicius Placco

We investigate the evolution of the abundance of fluorine in the Milky Way thick and thin discs by means of detailed chemical evolution models compared with recent observational data. The chemical evolution models adopted here have already…

星系天体物理 · 物理学 2020-08-19 Valeria Grisoni , Donatella Romano , Emanuele Spitoni , Francesca Matteucci , Nils Ryde , Henrik Jönsson

We analyze a sample of 3,944 low-resolution (R ~ 2000) optical spectra from the Sloan Digital Sky Survey (SDSS), focusing on stars with effective temperatures 5800 < Teff < 6300 K, and distances from the Milky Way plane in excess of 5 kpc,…

This work presents a uniform and homogeneous study of chemical abundances of refractory elements in 101 stars with and 94 without known planetary companions. We carry out an in-depth investigation of the abundances of Si, Ca, Sc, Ti, V, Cr,…

天体物理学 · 物理学 2009-11-11 G. Gilli , G. Israelian , A. Ecuvillon , N. C. Santos , M. Mayor

We explore the elemental abundance features of metal-rich disk stars, highlighting the comparisons made with those of the recently revealed Galactic bulge stars. A similarity between two of the comparisons leads to a new theoretical picture…

天体物理学 · 物理学 2009-11-13 Takuji Tsujimoto

We present interstellar elemental abundance measurements derived from Space Telescope Imaging Spectrograph echelle observations of 47 sight lines extending up to 6.5 kpc through the Galactic disk. These paths probe a variety of interstellar…

天体物理学 · 物理学 2009-11-13 Stefan I. B. Cartledge , J. T. Lauroesch , David M. Meyer , Ulysses J. Sofia

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…

太阳与恒星天体物理 · 物理学 2014-09-05 P. E. Nissen , Y. Q. Chen , L. Carigi , W. J. Schuster , G. Zhao

The study of the Milky Way stellar discs in the context of galaxy formation is discussed. In particular we explore the properties of the Milky Way disc using a new sample of about 550 dwarf stars for which we have recently obtained…

天体物理学 · 物理学 2009-11-13 S. Feltzing , T. Bensby

CONTEXT:The detailed chemical abundances of extremely metal-poor (EMP) stars are key guides to understanding the early chemical evolution of the Galaxy. Most existing data are, however, for giant stars which may have experienced internal…

Oxygen abundances for a large sample of dwarf and giant stars kinematically selected to be part of the Galactic thin and thick disks have been determined from a non-LTE analysis of the O I triplet lines at 777 nm. The abundance analysis was…

天体物理学 · 物理学 2009-11-11 I. Ramirez , C. Allende Prieto , D. L. Lambert

We study the detailed properties of the radial metallicity gradient in the stellar disk of our Galaxy to constrain its chemical and structural evolution. For this purpose we select and analyze $\sim$ 18,500 disk stars taken from two…

星系天体物理 · 物理学 2015-06-19 Daisuke Toyouchi , Masashi Chiba

The spatial distribution of elemental abundances in the disc of our Galaxy gives insights both on its assembly process and subsequent evolution, and on the stellar nucleogenesis of the different elements. Gradients can be traced using…