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We present an abundance analysis based on high dispersion and high signal-to-noise ratio Keck spectra of a very highly microlensed Galactic bulge dwarf, OGLE-2007-BLG-349S, with Teff ~ 5400 K. The amplification at the time the spectra were…

Astrophysics · Physics 2009-11-13 Judith G. Cohen , Wenjin Huang , A. Udalski , Andrew Gould , Jennifer Johnson

We present a detailed elemental abundance study of 90 F and G dwarf, turn-off and subgiant stars in the Galactic bulge. Based on high-resolution spectra acquired during gravitational microlensing events, stellar ages and abundances for 11…

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

Photometric investigations have revealed that Galactic globular clusters exhibit internal metallicity variations amongst the so-called first-population stars, until now considered to have a homogeneous initial chemical composition. This is…

Astrophysics of Galaxies · Physics 2022-12-28 C. Lardo , M. Salaris , S. Cassisi , N. Bastian , A. Mucciarelli , I. Cabrera-Ziri , E. Dalessandro

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…

Astrophysics · Physics 2009-11-13 K. Cunha , V. Smith , K. Sellgren , R. Blum , S. Ramirez , D. Terndrup

We present measurements of the abundances of chromium, cobalt, and nickel in 4113 red giants, including 2277 stars in globular clusters, 1820 stars in the Milky Way's dwarf satellite galaxies, and 16 field stars. We measured the abundances…

Solar and Stellar Astrophysics · Physics 2019-07-01 Evan N. Kirby , Justin L. Xie , Rachel Guo , Mikhail Kovalev , Maria Bergemann

We report the results of an analysis of CN and CH band strengths among a large sample of 47 Tucanae main-sequence and turn-off stars presented earlier by Harbeck et al. The resulting C and N abundances derived from synthetic spectra…

Astrophysics · Physics 2015-06-24 Michael M. Briley , Daniel Harbeck , Graeme H. Smith , Eva K. Grebel

Variations in chemical abundances with evolutionary phase have been identified among stars in globular and open clusters with a wide range of metallicities. In the metal-poor clusters, these variations compare well with predictions from…

Solar and Stellar Astrophysics · Physics 2023-12-18 T. Nordlander , P. Gruyters , O. Richard , A. J. Korn

[ABRIDGED] Metal-rich globular clusters provide important tracers of the formation of our Galaxy. Moreover, and not less important, they are very important calibrators for the derivation of properties of extra-galactic metal-rich stellar…

Astrophysics · Physics 2009-11-13 S. Feltzing , F. Primas , R. A. Johnson

We test the performance of our analysis technique for integrated-light spectra by applying it to seven well-studied Galactic GCs that span a wide range of metallicities. Integrated-light spectra were obtained by scanning the slit of the…

Solar and Stellar Astrophysics · Physics 2017-05-10 S. S. Larsen , J. P. Brodie , J. Strader

This paper presents abundances for 12 red giants of the old open cluster Collinder 261 based on spectra from VLT/UVES. Abundances were derived for Na, Mg, Si, Ca, Mn, Fe, Ni, Zr and Ba. We find the cluster has a solar-level metallicity of…

Astrophysics · Physics 2008-11-26 G. M. De Silva , K. C. Freeman , M. Asplund , J. Bland-Hawthorn , M. S. Bessell , R. Collet

Star clusters, particularly those objects in the disk-bulge-halo interface are as of yet poorly charted, albeit carrying important information about the formation and the structure of the Milky Way. Here, we present a detailed chemical…

Astrophysics of Galaxies · Physics 2017-12-27 Andreas Koch , Terese T. Hansen , Andrea Kunder

The study of open-cluster chemical abundances provides insights on stellar nucleosynthesis processes and on Galactic chemo-dynamical evolution. In this paper we present an extended abundance analysis of 10 species (Fe, Ni, Cr, V, Sc, Si,…

We present a chemical abundance study of three inner old halo clusters NGC 6287, NGC 6293, and NGC 6541, finding [Fe/H] = -2.01 +/- 0.05, -1.99 +/- 0.02, and -1.76 +/- 0.02, respectively, and our metallicity measurements are in good…

Astrophysics · Physics 2009-11-07 Jae-Woo Lee , Bruce W. Carney

We present a chemical composition analysis of 36 giant stars in mildly metal-poor globular cluster M5. In comparing the M5 results to those obtained in M4, a cluster previously considered to be a ``twin'' in age, metallicity and chemical…

Previous surveys in a few metal-poor globular clusters (GCs) showed that the determination of abundances for Li and proton-capture elements offers a key tool to address the intracluster pollution scenario. In this Letter, we present Na, O,…

Solar and Stellar Astrophysics · Physics 2015-05-18 Valentina D'Orazi , Sara Lucatello , Raffaele Gratton , Angela Bragaglia , Eugenio Carretta , Zhixia Shen , Simone Zaggia , .

We derive [K/Fe] abundance ratios for 119 stars in the globular cluster NGC 2808, all of them having O, Na, Mg and Al abundances homogeneously measured in previous works. We detect an intrinsic star-to-star spread in the Potassium…

Solar and Stellar Astrophysics · Physics 2015-06-23 A. Mucciarelli , M. Bellazzini , T. Merle , B. Plez , E. Dalessandro , R. Ibata

The location of the Scutum Red-Supergiant (RSG) clusters at the end of the Galactic Bar makes them an excellent probe of the Galaxy's secular evolution; while the clusters themselves are ideal testbeds in which to study the predictions of…

This research forms part of an investigation into heavy element abundances in Asymptotic Giant Branch (AGB) stars in various stellar environments. Seven giant stars in the southern globular cluster 47 Tuc have been observed using the…

Astrophysics · Physics 2008-11-26 E. C. Wylie , P. L. Cottrell , C. A. Sneden , J. C. Lattanzio

We have carried out a big FLAMES survey of 10 Galactic open clusters aiming at different goals. One of them is the determination of chemical abundances, in order to put constraints on the radial metallicity gradient in the disk and its…

Astrophysics · Physics 2009-11-13 P. Sestito , S. Randich , A. Bragaglia
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