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相关论文: Abundances of alpha-Process Elements in Thin-Disk,…

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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…

天体物理学 · 物理学 2009-11-11 T. V. Nykytyuk , T. V. Mishenina

In this paper, we aim to derive high-precision alpha-element abundances using CRIRES high-resolution IR spectra of 72 cool M giants of the inner Galactic bulge. Silicon, magnesium, and calcium abundances were determined by fitting a…

We study the enrichment histories for nine elements, C, four alpha-elements of Mg, Si, Ca, and Ti, Sc, and three iron-peak elements of Co, Ni, and Zn, by using a large number of stellar data, collected by the Stellar Abundances for Galactic…

星系天体物理 · 物理学 2015-06-17 Shimako Yamada , Takuma Suda , Yutaka Komiya , Wako Aoki , Masayuki Y. Fujimoto

ABRIDGED: METHODS: We have conducted a high-resolution spectroscopic study of 714 F and G dwarf and subgiant stars in the Solar neighbourhood. The star sample has been kinematically selected to trace the Galactic thin and thick disks to…

星系天体物理 · 物理学 2015-06-17 T. Bensby , S. Feltzing , M. S. Oey

Differential abundances of C, O, Mg, Al, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Y, and Zr were determined from high signal-to-noise VLT/UVES spectra for 25 turnoff stars with -2.4 < [Fe/H] < -1.3. Effective temperatures were obtained from…

星系天体物理 · 物理学 2026-05-01 Poul Erik Nissen , Anish Amarsi

ABRIDGED: To compare the chemistries of stars in the Milky Way dSph galaxies with stars in the Galaxy, we have compiled a large sample of Galactic stellar abundances from the literature. As found in previous studies, the [alpha/Fe] ratios…

天体物理学 · 物理学 2009-11-10 K. A. Venn , M. Irwin , M. D. Shetrone , C. A. Tout , V. Hill , E. Tolstoy

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),…

太阳与恒星天体物理 · 物理学 2015-06-12 I. Ramirez , C. Allende Prieto , D. L. Lambert

To understand the formation and evolution of the different stellar populations within our Galaxy it is essential to combine detailed kinematical and chemical information for large samples of stars. We derive chemical abundances of Cu, Zn,…

太阳与恒星天体物理 · 物理学 2017-10-25 E. Delgado Mena , M. Tsantaki , V. Zh. Adibekyan , S. G. Sousa , N. C. Santos , J. I. González Hernández , G. Israelian

Knowledge of abundance ratios as functions of metallicity can lead to insights on the origin and evolution of our Galaxy and its stellar populations. We aim to trace the chemical evolution of the neutron-capture elements Sr, Zr, La, Ce, Nd,…

太阳与恒星天体物理 · 物理学 2017-04-26 Chiara Battistini , Thomas Bensby

We provide the whole set of Lick indices from CN1 to TiO2 of Simple Stellar Population models with, for the first time, variable element abundance ratios, [alpha/Fe]=0.0, 0.3, 0.5, [alpha/Ca]=-0.1, 0.0, 0.2, 0.5, and [alpha/N]=-0.5, 0.0.…

天体物理学 · 物理学 2009-11-07 Daniel Thomas , Claudia Maraston , Ralf Bender

We present a detailed analysis of 26 barium stars, including dwarf barium stars, providing their atmospheric parameters (Teff, log g, [Fe/H], vt) and elemental abundances. We aim at deriving gravities and luminosity classes of the sample…

天体物理学 · 物理学 2009-11-11 Dinah M. Allen , Beatriz Barbuy

We present a homogeneous set of accurate atmospheric parameters for a complete sample of very and extremely metal-poor stars in the dwarf spheroidal galaxies (dSphs) Sculptor, Ursa Minor, Sextans, Fornax, Bo\"otes I, Ursa Major II, and Leo…

太阳与恒星天体物理 · 物理学 2017-08-30 L. Mashonkina , P. Jablonka , Yu. Pakhomov , T. Sitnova , P. North

Magnesium is one of the important elements in stellar physics as an electron donor and in Galactic Archaeology as a discriminator of different stellar populations. However, previous studies of Mg I and Mg II lines in metal-poor benchmark…

太阳与恒星天体物理 · 物理学 2024-08-07 T. Matsuno , A. M. Amarsi , M. Carlos , P. E. Nissen

Oxygen abundances of 67 dwarf stars in the metallicity range -1.6<[Fe/H]<-0.4 are derived from a non-LTE analysis of the 777 nm O I triplet lines. These stars have precise atmospheric parameters measured by Nissen and Schuster, who find…

太阳与恒星天体物理 · 物理学 2015-06-11 I. Ramirez , J. Melendez , J. Chaname

Context. Elemental abundances are of prime importance to help us reconstruct the origin and evolution of stars and galaxies in our Universe. Sulfur abundances have not been as heavily studied as other elements, so some details regarding its…

太阳与恒星天体物理 · 物理学 2020-02-26 Ana Rita Costa Silva , Elisa Delgado Mena , Maria Tsantaki

We take advantage of the Gaia-ESO Survey iDR4 bulge data to search for abundance anomalies that could shed light on the composite nature of the Milky Way bulge. The alpha-elements (Mg, Si, and whenever available, Ca) abundances, and their…

Abundances of five elements, Na, Mg, Al, Si, and Sr, are investigated for 44 very metal-poor stars (-4.0 < [Fe/H] < -1.5) in the Galactic halo system based on an Local Thermodinamic Equilibrium (LTE) analysis of high-resolution…

Context. Recent observations of the Bulge, e.g., its X-shape, cylindrical stellar motions, and a potential fraction of young stars propose that it formed through secular evolution of the disk and not through gas dissipation and/or mergers,…

星系天体物理 · 物理学 2019-05-29 M. Lomaeva , H. Jönsson , N. Ryde , M. Schultheis , B. Thorsbro

We investigate if there is a difference in the lithium abundances of stars belonging to two halo populations of F and G main-sequence stars previously found to differ in [alpha/Fe] for the metallicity range -1.4 < [Fe/H] < -0.7. Li…

星系天体物理 · 物理学 2015-06-05 P. E. Nissen , W. J. Schuster