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相关论文: Light, Alpha, and Fe-Peak Element Abundances in th…

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The Milky Way bulge is an important tracer of the early formation and chemical enrichment of the Galaxy. The abundances of different iron-peak elements in field bulge stars can give information on the nucleosynthesis processes that took…

太阳与恒星天体物理 · 物理学 2020-08-19 H. Ernandes , B. Barbuy , A. Friaça , V. Hill , M. Zoccali , D. Minniti , A. Renzini , S. Ortolani

We measure chemical abundances for over 20 elements of 15 N-rich field stars with high resolution ($R \sim 30000$) optical spectra. We find that Na, Mg, Al, Si, and Ca abundances of our N-rich field stars are mostly consistent with those of…

星系天体物理 · 物理学 2021-06-02 Jincheng Yu , Baitian Tang , J. G. Fernandez-Trincado , Douglas Geisler , Hongliang Yan , M. Soto

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 compute the chemical evolution of the Galactic bulge in the context of an inside-out model for the formation of the Milky Way. The model contains updated stellar yields from massive stars. The main purpose of the paper is to compare the…

天体物理学 · 物理学 2009-11-13 Silvia K. Ballero , Francesca Matteucci , Livia Origlia , R. Michael Rich

We report the first high resolution, detailed abundances of 21 elements for giants in the Galactic bulge/bar within $1^\circ$ of the Galactic plane, where high extinction has rendered such studies challenging. Our high S/N and…

Based on the medium-high resolution (R~ 20,000), modest signal-to-noise ratio (S/N > 70) FLAMES-GIRAFFE spectra, we investigated the copper abundances of 129 red giant branch stars in the Galactic bulge with [Fe/H] from -1.14 to 0.46 dex.…

太阳与恒星天体物理 · 物理学 2019-11-26 X. D. Xu , J. R. Shi , H. L Yan

AIMS: We spectroscopically characterize the Galactic Bulge to infer its star formation timescale, compared to the other Galactic components, through the chemical signature on its individual stars. METHODS: We derived iron and oxygen…

天体物理学 · 物理学 2010-01-07 M. Zoccali , A. Lecureur , B. Barbuy , V. Hill , A. Renzini , D. Minniti , Y. Momany , A. Gomez , S. Ortolani

It is debated whether the Milky Way bulge has the characteristics of a classical bulge sooner than those of a pseudobulge. Detailed abundance studies of bulge stars is a key to investigate the origin, history, and classification of the…

We derive abundance ratios for nine stars in the relatively high-metallicity bulge globular cluster NGC 6380. We find a mean cluster metallicity between [Fe/H]$= -0.80$ and $-0.73$, with no clear evidence for a variation in iron abundances…

We present an R=45,000 Keck spectrum of the microlensed Galactic bulge G-dwarf OGLE-2006-BLG-265, which has a high (~60) signal-to-noise ratio despite its short (15 min) exposure time because the source was magnified by A~135. While it is…

We provide a high dispersion line-by-line abundance analysis of five red HB stars in the extremely metal rich galactic globular cluster NGC 6553. These red HB stars are significantly hotter than the very cool stars near the tip of the giant…

天体物理学 · 物理学 2009-10-31 Judith G. Cohen , Raffaele G. Gratton , Bradford B. Behr , Eugenio Carretta

We present abundance analyses based on high dispersion and high signal-to-noise ratio Magellan spectra of two highly microlensed Galactic bulge stars in the region of the main sequence turnoff with Teff ~ 5650 K. We find that…

太阳与恒星天体物理 · 物理学 2009-06-25 Judith G. Cohen , Ian B. Thompson , Takahiro Sumi , Ian Bond , Andrew Gould , Jennifer A. Johnson , Wenjin Huang , Greg Burley

We present the abundance analysis of stars from the tip of the red giant branch (RGB) to below the RGB-bump in the globular cluster NGC 2808, based on high resolution echelle spectra. We derived abundances of Al, alpha-process elements (Si…

天体物理学 · 物理学 2009-11-11 Eugenio Carretta

Context: The study of chemical abundance patterns in globular clusters is of key importance to constrain the different candidates for intra-cluster pollution of light elements. Aims: We aim at deriving accurate abundances for a large range…

太阳与恒星天体物理 · 物理学 2014-12-10 A. O. Thygesen , L. Sbordone , S. Andrievsky , S. Korotin , D. Yong , S. Zaggia , H. -G. Ludwig , R. Collet , M. Asplund , F. D'Antona , J. Meléndez , A. D'Ercole

We present emission line strengths, abundances, and element ratios (X/O for Ne, S, Cl, and Ar) for a sample of 38 Galactic disk planetary nebulae (PNe) consisting primarily of Peimbert classification Type I. Spectrophotometry for these PNe…

太阳与恒星天体物理 · 物理学 2015-05-18 J. B. Milingo , K. B. Kwitter , R. B. C. Henry , S. P. Souza

We present abundance ratios for 23 elements with respect to Fe in a sample of stars with a wide range in luminosity, from luminous giants to stars near the turnoff, in the globular cluster M71. The analyzed spectra, obtained with HIRES at…

天体物理学 · 物理学 2009-11-07 Solange V. Ramirez , Judith G. Cohen

Oxygen and zinc in the Galactic bulge are key elements for the understanding of the bulge chemical evolution. Oxygen-to-iron abundance ratios provide a most robust indicator of the star formation rate and chemical evolution of the bulge.…

太阳与恒星天体物理 · 物理学 2018-07-18 C. R. da Silveira , B. Barbuy , A. C. S. Friaça , V. Hill , M. Zoccali , M. Rafelski , O. A. Gonzalez , D. Minniti , A. Renzini , S. Ortolani

We present mid-infrared Spitzer spectra of eleven planetary nebulae in the Galactic Bulge. We derive argon, neon, sulfur, and oxygen abundances for them using mainly infrared line fluxes combined with some optical line fluxes from the…

天体物理学 · 物理学 2008-06-17 S. Gutenkunst , J. Bernard-Salas , S. R. Pottasch , G. C. Sloan , J. R. Houck

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…

天体物理学 · 物理学 2009-11-11 David Yong , Frank Grundahl , Poul Erik Nissen , Henrik Robenhagen Jensen , David L. Lambert

From a detailed elemental abundance analysis of 102 F and G dwarf stars we present abundance trends in the Galactic thin and thick disks for 14 elements (O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Zn, Y, Ba, and Eu). Stellar parameters and…

天体物理学 · 物理学 2007-05-23 T. Bensby , S. Feltzing , I. Lundström , I. Ilyin