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Globular clusters (GCs) in the outer Milky Way halo are important tracers of the assembly history of our Galaxy. Only a few of these objects show spreads in heavier elements beyond the canonical light-element variations that have…

Astrophysics of Galaxies · Physics 2019-07-05 Andreas Koch , Siyi Xu , R. Michael Rich

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…

Solar and Stellar Astrophysics · Physics 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

High-resolution H-band spectra of five bright field K, M, and MS giants, obtained from the archives of the Kitt Peak National Observatory (KPNO) Fourier Transform Spectrometer (FTS), are analyzed to determine chemical abundances of 16…

We have determined Al, $\alpha$, Fe-peak, and neutron capture elemental abundances for five red giant branch (RGB) stars in the Galactic globular cluster M10. Abundances were determined using equivalent width analyses of moderate resolution…

We present an abundance analysis based on high resolution spectra of 8 stars selected to span the full range in metallicity in the Draco dwarf spheroidal galaxy. We find [Fe/H] for the sample stars ranges from -1.5 to -3.0 dex. Combining…

Astrophysics of Galaxies · Physics 2009-08-05 Judith G. Cohen , Wenjin Huang

The high-mass (M$>$2 \Msolar{}) Kepler red giant stars are less well-studied than their lower-mass counterparts. In the previous article, we presented a sample of 48 high-mass Kepler red giants and measured their asteroseismic parameters.…

We present an analysis of the relative abundance features of a number of chemical elements in the atmospheres of metal-rich ($\rm{[Fe/H]} > -1.0$) Galactic-field RR~Lyrae variable stars and the kinematic characteristics of these stars. We…

Solar and Stellar Astrophysics · Physics 2024-08-07 M. L. Gozha , V. A. Marsakov , V. V. Koval'

In a framework where galaxies form hierarchically, extended stellar haloes are predicted to be an ubiquitous feature around Milky Way-like galaxies and to consist mainly of the shredded stellar component of smaller galactic systems. The…

Astrophysics of Galaxies · Physics 2017-12-20 G. Battaglia , P. North , P. Jablonka , M. Shetrone , D. Minniti , M. Díaz , E. Starkenburg , M. Savoy

Chemical abundances are presented for 19 elements in a sample of 63 red giants in the Carina dwarf spheroidal galaxy (dSph), based on homogeneous 1D/LTE model atmosphere analyses of our own observations (32 stars) and data available in the…

Astrophysics of Galaxies · Physics 2017-07-26 John E. Norris , David Yong , Kim A. Venn , Gerard Gilmore , Luca Casagrande , Aaron Dotter

The compositions of stars are a critical diagnostic tool for many topics in astronomy such as the evolution of our Galaxy, the formation of planets, and the uniqueness of the Sun. Previous spectroscopic measurements indicate a large…

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

Chemical elements in the hot medium permeating early-type galaxies, groups, and clusters make them an excellent laboratory for studying metal enrichment and cycling processes in the largest scales of the universe. Here, we report the…

Astrophysics of Galaxies · Physics 2023-08-10 Kotaro Fukushima , Shogo B. Kobayashi , Kyoko Matsushita

Stellar evolution models predict that internal mixing should cause some sodium overabundance at the surface of red giants more massive than ~ 1.5--2.0 Msun. The surface aluminium abundance should not be affected. Nevertheless, observational…

Star-to-star abundance variations of C, N, O, Na and Al in globular-cluster red giants have been recently supplemented by the finding that [Mg/Fe] is depleted in stars with extremely large [Al/Fe] (Shetrone 1996a). This and other new…

Astrophysics · Physics 2007-05-23 P. A. Denissenkov , G. S. Da Costa , J. E. Norris , A. Weiss

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

I present details of the variations of several hundred red giant stars on time scales of a few hours to a few days from Hubble Space Telescope (HST) observations of a low-extinction galactic bulge sample from an intensive seven day…

Astrophysics · Physics 2009-11-13 Ronald L. Gilliland

Low mass dwarf spheroidal galaxies are key objects for our understanding of the chemical evolution of the pristine Universe and the Local Group of galaxies. Abundance ratios in stars of these objects can be used to better understand their…

Astrophysics of Galaxies · Physics 2016-03-09 P. François , L. Monaco , P. Bonifacio , C. Moni Bidin , D. Geisler , L. Sbordone

This paper investigates the peculiar behaviour of the light even (alpha-elements) and odd atomic number elements in red giants in the galactic bulge, both in terms of the chemical evolution of the bulge, and in terms of possible deep-mixing…

Astrophysics · Physics 2009-11-11 A. Lecureur , V. Hill , M. Zoccali , B. Barbuy , A. Gomez , D. Minniti , S. Ortolani , A. Renzini

Sulfur and zinc are chemically volatile elements, which play significant roles as depletion-free tracers in studying galactic chemical evolution. However, regarding red giants having evolved off the main sequence, reliable abundance…

Solar and Stellar Astrophysics · Physics 2016-09-07 Yoichi Takeda , Masashi Omiya , Hiroki Harakawa , Bun'ei Sato

High-resolution infrared spectra (R=50,000) have been obtained for twelve red-giant members of the LMC with the Gemini South 8.3-meter telescope plus Phoenix spectrometer. Quantitative chemical abundances of carbon-12, carbon-13,…