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Related papers: M22: A [Fe/H] Abundance Range Revealed

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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 report on detailed abundances of giants in the Galactic bulge, measured with the HIRES echelle spectrograph on the 10-m Keck telescope. We also review other work on the bulge field population and globular clusters using Keck/HIRES. Our…

Astrophysics · Physics 2015-06-24 R. M. Rich , A. McWilliam

We present CN and CH indices and CaII triplet metallicities for 34 giant stars and chemical abundances for 33 elements in 14 giants in the globular cluster M2. Assuming the program stars are cluster members, our analysis reveals (i) an…

We have used UVES on VLT-UT2 to take spectra of 15 red giants in the Sculptor, Fornax, Carina and Leo I dwarf spheroidal galaxies. We measure the abundances of alpha, iron peak, s and r-process elements. No dSph giants in our sample show…

Astrophysics · Physics 2011-03-28 M. Shetrone , K. A. Venn , E. Tolstoy , F. Primas , V. Hill , A. Kaufer

With an aim to examine whether the surface oxygen composition suffers any appreciable change due to evolution-induced mixing of nuclear-processed material in the envelope of red giants, abundance determinations for O/Fe/Ni based on the…

Solar and Stellar Astrophysics · Physics 2015-06-23 Yoichi Takeda , Satoshi Honda

There is increasing evidence for the presence of multiple red giant branches (RGBs) in the color-magnitude diagrams of massive globular clusters (GCs). In order to investigate the origin of this split on the RGB, we have performed new…

Aims.The aim of this study is a detailed abundance analysis of the newly discovered r-rich star HE 1405 0822, which has [Fe=H]=-2.40. This star shows enhancements of both r- and s-elements, [Ba/Fe]= +1.95 and [Eu/Fe]=1.54, for which reason…

Solar and Stellar Astrophysics · Physics 2016-11-26 W. Y. Cui , T. Sivarani , N. Christlieb

We present a detailed abundance analysis for 21 elements based on high dispersion, high spectral resolution Keck spectra for four members of the outer halo ``young'' Galactic globular cluster Pal 12. All four stars show identical abundance…

Astrophysics · Physics 2015-06-24 Judith Cohen

A new calibration of the Stroemgren (b-y),m_1 diagram in terms of iron abundance of red giants is presented. This calibration is based on a homogeneous sample of giants in the globular clusters omega Centauri, M22, and M55 as well as field…

Astrophysics · Physics 2007-05-23 Michael Hilker

We present deep CCD photometry in the VI passbands using the WIYN 3.5m telescope of a field located approximately 20' southeast of the center of M33; this field includes the region studied by Mould & Kristian in their 1986 paper. The…

Astrophysics · Physics 2009-11-10 Glenn P. Tiede , Ata Sarajedini , Michael K. Barker

Long-slit spectroscopy has been obtained for a sample of 22 blue dwarf galaxies selected in the direction of the Virgo Cluster as part of a larger sample of Virgo blue dwarf galaxies for which deep Halpha imaging has been collected. Most of…

Astrophysics · Physics 2009-11-07 J. M. Vilchez , J. Iglesias-Paramo

Detailed chemical composition of stars is of prime interest for a range of topics in modern stellar astrophysics, such as the chemical evolution of the Galaxy or the formation, composition, and structure of exoplanets. In this work, we…

Solar and Stellar Astrophysics · Physics 2024-01-18 C. Duque-Arribas , H. M. Tabernero , D. Montes , J. A. Caballero

Recent surveys uncovered new Young Massive Clusters (YMCs) that host dozens of Red Supergiants (RSGs) in the inner Milky Way. These clusters are ideal for studying the most recent and violent star formation events in the inner Galaxy.…

Astrophysics of Galaxies · Physics 2020-07-15 Randa Asa'd , M. Kovalev , B. Davies , V. D. Ivanov , M. Rejkuba , A. Gonneau , S. Hernandez , C. Lardo , M. Bergemann

We present magnesium abundances derived from high resolution spectra using several Mg I and two high excitation Mg II lines for 19 metal-poor stars with [Fe/H] values between -1.1 and +0.2. The main goal is to search for systematic…

Astrophysics · Physics 2016-08-30 Carlos Abia , Lyudmila Mashonkina

We provide a grid of PHOENIX spectra of red giant and supergiant stars, that extend through optical and near-IR wavelengths. For the first time, models are also provided with modified surface abundances of C, N and O, as a step towards…

Astrophysics · Physics 2009-11-13 A. Lançon , P. H. Hauschildt , D. Ladjal , M. Mouhcine

The Galactic Centre (GC) has experienced a high degree of recent star-forming activity, as evidenced by the large number of massive stars currently residing there. The relative abundances of chemical elements in the GC may provide insights…

We present moderate (R~$\approx$~2,700) and high resolution (R~$\approx$~22,000) 2.0$-$2.4 \micron\ spectroscopy of the central 0.1 square arcseconds of the Galaxy obtained with NIRSPEC, the facility near-infrared spectrometer for the Keck…

We present measurements of [Fe/H] for six M supergiant stars and three giant stars within 0.5 pc of the Galactic Center (GC) and one M supergiant star within 30 pc of the GC. The results are based on high-resolution (lambda / Delta lambda…

We present near-IR spectroscopy of red supergiant (RSG) stars in NGC 6822, obtained with the new VLT-KMOS instrument. From comparisons with model spectra in the J-band we determine the metallicity of 11 RSGs, finding a mean value of [Z] =…

Solar and Stellar Astrophysics · Physics 2015-06-23 L. R. Patrick , C. J. Evans , B. Davies , R-P. Kudritzki , J. Z. Gazak , M. Bergemann , B. Plez , A. M. N. Ferguson

NGC 6558 is a bulge globular cluster with a blue horizontal branch (BHB), combined with a metallicity of [Fe/H]~-1.0. It is similar to HP 1 and NGC 6522, which could be among the oldest objects in the Galaxy. Element abundances in these…

Solar and Stellar Astrophysics · Physics 2018-11-28 B. Barbuy , L. Muniz , S. Ortolani , H. Ernandes , B. Dias , I. Saviane , L. Kerber , E. Bica , A. Pérez-Villegas , L. Rossi , E. V. Held
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