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Related papers: Complexity on Small Scales III: Iron and alpha Ele…

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We present the chemical composition of 206 red giant branch stars members of the Small Magellanic Cloud (SMC) using optical, high-resolution spectra collected with the multi-object spectrograph FLAMES-GIRAFFE at the ESO Very Large…

Astrophysics of Galaxies · Physics 2023-03-29 A. Mucciarelli , A. Minelli , M. Bellazzini , C. Lardo , D. Romano , L. Origlia , F. R. Ferraro

[ABRIDGED] We report the results of a high-resolution spectroscopic survey of all the stars more luminous than Mv = 6.5 mag within 14.5 pc from the Sun. We derive stellar parameters and perform a preliminary abundance and kinematic analysis…

Astrophysics · Physics 2016-08-30 Carlos Allende Prieto , Paul S. Barklem , David L. Lambert , Katia Cunha

Based on high resolution, high signal-to-noise (S/N) ratio spectra from Keck/HIRES, we have determined abundances of 20 elements for 18 Ba candidates. The parameter space of these stars are in the range of 4880 $\leq$ $\rm{T_{eff}}$ $\leq$…

Solar and Stellar Astrophysics · Physics 2022-01-05 Shuai Liu , Liang Wang , Jian-Rong Shi , Zhen-Yu Wu , Hong-Liang Yan , Qi Gao , Chun-Qian Li

We present alpha element to iron abundance ratios, [$\alpha$/Fe], for four stars in the outer stellar halo of the Andromeda Galaxy (M 31). The stars were identified as high-likelihood field halo stars by Gilbert et al. (2012) and lie at…

Astrophysics of Galaxies · Physics 2015-06-23 Luis C. Vargas , Karoline M. Gilbert , Marla C. Geha , Erik J. Tollerud , Evan N. Kirby , Puragra Guhathakurta

We have obtained new detailed abundances of the Fe-group elements Sc through Zn (Z=21-30) in three very metal-poor ([Fe/H] $\approx -3$) stars: BD 03 740, BD -13 3442 and CD -33 1173. High-resolution ultraviolet HST/STIS spectra in the…

We report results from the high resolution spectral analysis of the 107 metal rich (mostly [Fe/H]$\ge$7.67 dex) target stars from the Calan-Hertfordshire Extrasolar Planet Search program observed with HARPS. Using our procedure of finding…

Solar and Stellar Astrophysics · Physics 2017-05-10 Oleksiy M. Ivanyuk , James S. Jenkins , Yakiv V. Pavlenko , Hugh R. A. Jones , David J. Pinfield

HARPS-N spectra with S/N > 250 and MARCS model atmospheres were used to derive abundances of C, O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Zn, and Y in ten stars from the Kepler LEGACY sample (including the binary pair 16 Cyg A and B) selected…

Solar and Stellar Astrophysics · Physics 2017-12-13 P. E. Nissen , V. Silva Aguirre , J. Christensen-Dalsgaard , R. Collet , F. Grundahl , D. Slumstrup

Abundances for alpha-elements and Fe in about 150 field subdwarfs and early subgiants with accurate parallaxes and kinematic data are used to discuss the run of abundance ratios in metal-poor stars in the solar neighborhood. Based on…

With abundances and 2{\sigma} upper limits of fluorine (F) in seven metal-poor field giants, nucleosynthesis of stellar F at low metallicity is discussed. The measurements are derived from the HF(1-0) R9 line at 23358{\AA} using…

Astrophysics of Galaxies · Physics 2013-02-19 H. N. Li , H. -G. Ludwig , E. Caffau , N. Christlieb , G. Zhao

We have obtained high-resolution, high S/N spectra for six red giants in omega Cen: three belonging to the recently discovered, metal-rich Red Giant Branch (RGB-a, Pancino et al. 2000) and three to the metal intermediate population…

Astrophysics · Physics 2009-10-08 E. Pancino , L. Pasquini , V. Hill , F. R. Ferraro , M. Bellazzini

We present alpha-element abundances of Mg, Si, and Ti for a large sample of field stars in two outer fields of the Fornax dwarf spheroidal galaxy (dSph), obtained with VLT/GIRAFFE (R~16,000). Due to the large fraction of metal-poor stars in…

For the first time we show the detailed late-stage chemical evolution history of small nearby dwarf spheroidal galaxy in the Local Group. We present the results of a high resolution (R$\sim$20000) FLAMES/GIRAFFE abundance study at ESO/VLT…

Medium resolution spectra of more than 400 subgiant and turn-off region stars in Omega Centauri were analysed. The observations were performed at the VLT/Paranal with FORS2/MXU. In order to determine the metallicities of the sample stars,…

Astrophysics · Physics 2007-05-23 Andrea Kayser , Michael Hilker , Tom Richtler , Philip G. Willemsen

We present Fe, Si, and Ca abundances for 61 giants in Plaut's Window (l=-1,b=-8.5) and Fe abundances for an additional 31 giants in a second, nearby field (l=0,b=-8) derived from high resolution (R~25,000) spectra obtained with the Blanco…

Solar and Stellar Astrophysics · Physics 2015-05-27 Christian I. Johnson , R. Michael Rich , Jon P. Fulbright , Elena Valenti , Andrew McWilliam

Classical chemical analyses may be affected by systematic errors that would cause observed abundance differences between dwarfs and giants. For some elements, however, the abundance difference could be real. We address the issue by…

Solar and Stellar Astrophysics · Physics 2015-05-18 G. Pace , J. Danziger , G. Carraro , J. Melendez , P. Francois , F. Matteucci , N. C. Santos , ;

We present the first detailed chemical abundance study of the ultra-faint dwarf galaxy Tucana II based on high-resolution Magellan/MIKE spectra of four red giant stars. The metallicity of these stars ranges from [Fe/H] = -3.2 to -2.6, and…

Astrophysics of Galaxies · Physics 2016-11-23 Alexander P. Ji , Anna Frebel , Rana Ezzeddine , Andrew R. Casey

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…

Astrophysics · Physics 2009-11-10 K. A. Venn , M. Irwin , M. D. Shetrone , C. A. Tout , V. Hill , E. Tolstoy

We present radial trends of metallicity ([Fe/H]) and abundance ratios ([X/Fe]) for several chemical elements -- including C, N, Na, and the so-called alpha-elements (O, Mg, Si, Ca, and Ti) -- in the bulge of M31, out to ~0.6kpc from the…

Astrophysics of Galaxies · Physics 2025-11-20 F. La Barbera , A. Vazdekis , F. Matteucci , E. Spitoni , A. Pasquali , I. Martín-Navarro

We report preliminary results concerning the detailed chemical composition of metal poor stars belonging to close ultra-faint dwarf galaxies (hereafter UfDSphs). The abundances have been determined thanks to spectra obtained with X-Shooter,…

Astrophysics of Galaxies · Physics 2015-06-04 P. François , L. Monaco , S. Villanova , M. Catelan , P. Bonifacio , M. Bellazzini , C. Moni Bidin , G. Marconi , D. Geisler , L. Sbordone

(Abridged) Extremely metal-poor stars contain the fossil records of the chemical composition of the early Galaxy. The NLTE profiles of the calcium lines were computed in a sample of 53 extremely metal-poor stars with a modified version of…