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Related papers: Abundance Patterns in Stars in the Bulge and Galac…

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Based on high-resolution spectra obtained during gravitational microlensing events we present a detailed elemental abundance analysis of 32 dwarf and subgiant stars in the Galactic bulge. [ABRIDGED], we now have 58 microlensed bulge dwarfs…

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…

Astrophysics · Physics 2009-11-07 Solange V. Ramirez , Judith G. Cohen

The chemical evolution of fluorine is investigated in a sample of Milky Way red giantstars that span a significant range in metallicity from [Fe/H] $\sim$ -1.3 to 0.0 dex. Fluorine abundances are derived from vibration-rotation lines of HF…

Solar and Stellar Astrophysics · Physics 2019-11-11 Rafael Guerço , Katia Cunha , Verne V. Smith , Christian R. Hayes , Carlos Abia , David L. Lambert , Henrik Jönsson , Nils Ryde

The abundances of iron and oxygen are homogeneously determined in a sample of 523 nearby (d<150 pc) FGK disk and halo stars with metallicities in the range -1.5<[Fe/H]<0.5. The oxygen abundances were inferred from a restricted non-LTE…

Astrophysics · Physics 2009-11-13 I. Ramirez , C. Allende Prieto , D. L. Lambert

The first measurement of the photospheric abundances in a star at the Galactic Center are presented. A detailed abundance analysis of the Galactic Center M2 supergiant IRS 7 was carried out using high-resolution near-infrared echelle…

Astrophysics · Physics 2009-10-31 John S. Carr , K. Sellgren , Suchitra C. Balachandran

Although there have been numerous studies of chemical abundances in the Galactic bulge, the central two degrees have been relatively unexplored due to the heavy and variable interstellar extinction, extreme stellar crowding, and the…

Astrophysics of Galaxies · Physics 2019-07-17 M. Schultheis , R. M. Rich , L. Origlia , N. Ryde , G. Nandakumar , B. Thorsbro , N. Neumayer

Our understanding of the chemical evolution of the Galactic bulge requires the determination of abundances in large samples of giant stars and planetary nebulae (PNe). We discuss PNe abundances in the Galactic bulge and compare these…

Astrophysics · Physics 2009-11-13 C. Chiappini , S. Gorny , G. Stasinska , B. Barbuy

High-resolution, high signal-to-noise spectral data are presented for four young B-type stars lying towards the Galactic Centre. Determination of their atmospheric parameters from their absorption line profiles, and uvby photometric…

Astrophysics · Physics 2009-10-31 S. J. Smartt , K. A. Venn , P. L. Dufton , D. J. Lennon , W. R. J. Rolleston , F. P. Keenan

We have determined detailed elemental abundances and stellar ages for a sample of now 38 microlensed dwarf and subgiant stars in the Galactic bulge. Stars with sub-solar metallicities are all old and have enhanced alpha-element abundances…

Astrophysics of Galaxies · Physics 2012-01-11 T. Bensby , S. Feltzing , A. Gould , J. A. Johnson , M. Asplund , D. Adén , J. Meléndez , J. G. Cohen , I. Thompson , S. Lucatello , A. Gal-Yam

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…

Astrophysics · Physics 2009-11-13 Silvia K. Ballero , Francesca Matteucci , Livia Origlia , R. Michael Rich

In this work, we study the formation and chemical evolution of the Galactic bulge with particular focus on the abundance pattern ([Mg/Fe] vs. [Fe/H]), metallicity and age distribution functions. We consider detailed chemical evolution…

In previous works, we computed abundances for the red giant in nearly four dozen S-type symbiotic systems (SySt). The abundances provide information about metallicity, evolutionary status, and possible memberships in Galactic stellar…

Solar and Stellar Astrophysics · Physics 2023-10-20 Cezary Gałan , Joanna Mikołajewska , Kenneth H. Hinkle , Richard R. Joyce

We present elemental abundances of 13 microlensed dwarf and subgiant stars in the Galactic bulge, which constitute the largest sample to date. We show that these stars span the full range of metallicity from Fe/H=-0.8 to +0.4, and that they…

The formation and evolution of the Milky Way bulge is not yet well understood and its classification is ambiguous. Constraints can, however, be obtained by studying the abundances of key elements in bulge stars. The aim of this study is to…

Solar and Stellar Astrophysics · Physics 2009-11-13 Nils Ryde , Bengt Edvardsson , Bengt Gustafsson , Kjell Eriksson , Hans Ulrich Kaufl , Ralf Siebenmorgen , Alain Smette

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 investigate stellar elemental abundance patterns at z = 0 in 8 low-mass (M_* = 10^6 - 10^9 M_sun) galaxies in the Feedback in Realistic Environments (FIRE-2) cosmological simulations. Using magnesium (Mg) as a representative…

Barium stars conserve important information on the s-process and the third dredge-up in intermediate mass stars. Their discovery in various environments is therefore of great help to test nucleosynthesis and mixing models. Our aim is to…

Solar and Stellar Astrophysics · Physics 2015-06-15 Thomas Lebzelter , Stefan Uttenthaler , Oscar Straniero , Bernhard Aringer

We derive abundances and central star parameters for 15 planetary nebulae (PNe) in M31: 12 in the bulge and 3 in a disk field 14 kpc from the nucleus. No single abundance value characterizes the bulge stars: although the median abundances…

Astrophysics · Physics 2009-10-31 George H. Jacoby , Robin Ciardullo

The abundances of O, Mg, Si and Fe in the intracluster medium of the Centaurus cluster are derived. The Fe abundance has a negative radial gradient. In solar units, the Si abundance is close to the Fe abundance, while the O and Mg…

Astrophysics · Physics 2009-11-11 Kyoko Matsushita , Hans Boehringer , Isao Takahashi , Yasushi Ikebe

We present a comprehensive chemical abundance analysis of five red giants and two horizontal branch (HB) stars towards the southern Galactic bulge, at (l,b)$\sim$(0$^{\rm o}$,-11$^{\rm o}$). Based on high-resolution spectroscopy obtained…

Astrophysics of Galaxies · Physics 2016-03-16 Andreas Koch , Andrew McWilliam , George W. Preston , Ian B. Thompson