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Related papers: Carbon-Enhanced Dwarf Stars Are Predominantly a Ha…

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This paper reports preliminary yet compelling kinematical inferences for N ~ 600 carbon-rich dwarf stars that demonstrate around 30% to 60% are members of the Galactic halo. The study uses a spectroscopically and non-kinematically selected…

Solar and Stellar Astrophysics · Physics 2018-04-25 J. Farihi , A. R. Arendt , H. S. Machado , L. J. Whitehouse

Carbon stars (with atmospheric C/O$>1$) range widely in temperature and luminosity, from low mass dwarfs to asymptotic giant branch stars (AGB). The main sequence dwarf carbon (dC) stars have inherited carbon-rich material from an AGB…

Solar and Stellar Astrophysics · Physics 2025-02-03 Benjamin R. Roulston , Naunet Leonhardes-Barboza , Paul J. Green , Evan Portnoi

Dwarf carbon stars are dominated by members of the Galactic halo and are thus likely carbon-enhanced metal-poor stars. In this work, a sample of 879 bona fide dwarf carbon stars are characterized by their ground-based light curves, and p<15…

Solar and Stellar Astrophysics · Physics 2026-05-13 Jonathan A. G. McLennan , Jay Farihi , Steven G. Parsons

We present Spitzer IRS spectra of four carbon stars located in the Galactic Halo and the thick disc. The spectra display typical features of carbon stars with SiC dust emission and C$_2$H$_2$ molecular absorption. Dust radiative transfer…

Solar and Stellar Astrophysics · Physics 2015-06-11 Eric Lagadec , Greg. C. Sloan , Albert. A. Zijlstra , Nicolas Mauron , J. R. Houck

Dwarf carbon stars make up the largest fraction of carbon stars in the Galaxy with around 1200 candidates known to date primarily from the Sloan Digital Sky Survey. They either possess primordial carbon-enhancements, or are polluted by mass…

Solar and Stellar Astrophysics · Physics 2018-07-04 Lewis J. Whitehouse , J. Farihi , P. J. Green , T. G. Wilson , J. P. Subasavage

Many characteristics of dwarf carbon stars are broadly consistent with a binary origin, including mass transfer from an evolved companion. While the population overall appears to have old-disc or halo kinematics, roughly 2$\,$per cent of…

Solar and Stellar Astrophysics · Physics 2021-08-04 L. J. Whitehouse , J. Farihi , I. D. Howarth , S. Mancino , N. Walters , A. Swan , T. G. Wilson , J. Guo

We present an analysis of the kinematic properties of stellar populations in the Galactic halo, making use of over 100,000 main sequence turnoff (MSTO) stars observed in the Sloan Digital Sky Survey. After dividing the Galactic halo into an…

Astrophysics of Galaxies · Physics 2020-01-08 Young Sun Lee , Timothy C. Beers , Young Kwang Kim

Precise abundance ratios are determined for 94 dwarf stars with 5200 < Teff < 6300 K, -1.6 < [Fe/H] < -0.4, and distances D < 335 pc. Most of them have halo kinematics, but 16 thick-disk stars are included. Equivalent widths of atomic lines…

Astrophysics of Galaxies · Physics 2015-05-18 Poul E. Nissen , William J. Schuster

The population of cool carbon (C) stars located far from the galactic plane is probably made of debris of small galaxies such as the Sagittarius dwarf spheroidal galaxy (Sgr), which are disrupted by the gravitational field of the Galaxy. We…

Astrophysics of Galaxies · Physics 2015-06-18 Nicolas Mauron , Kamo S. Gigoyan , Paul Berlioz-Arthaud , Alain Klotz

[ABRIDGED]We study the carbon abundances with a twofold objective. On the one hand, we want to evaluate the behaviour of carbon in the context of Galactic chemical evolution. On the other hand, we focus on the possible dependence of carbon…

Solar and Stellar Astrophysics · Physics 2021-12-01 E. Delgado Mena , V. Adibekyan , N. C. Santos , M. Tsantaki , J. I. González Hernández , S. G. Sousa , S. Bertrán de Lis

We present the first map of carbonicity, [C/Fe], for the halo system of the Milky Way, based on a sample of over 100,000 main-sequence turnoff stars with available spectroscopy from the Sloan Digital Sky Survey. This map, which explores…

Abundances of C, O, and Fe are determined for F and G main-sequence stars in the solar neighborhood in order to study trends and systematic differences in the C/Fe, O/Fe, and C/O ratios for stellar populations. Carbon abundances are…

Solar and Stellar Astrophysics · Physics 2014-09-05 P. E. Nissen , Y. Q. Chen , L. Carigi , W. J. Schuster , G. Zhao

Understanding the evolution of carbon and iron in the Milky Way's halo is of importance because these two elements play crucial roles constraining star formation, Galactic assembly, and chemical evolution in the early Universe. Here, we…

Oxygen and carbon are important elements in stellar populations. Their behavior refers to the formation history of the stellar populations. C and O abundances would also obviously influence stellar opacities and the overall metal abundance…

Solar and Stellar Astrophysics · Physics 2016-12-21 Z. S. Ge , S. L. Bi , Y. Q. Chen , T. D. Li , J. K. Zhao , K. Liu , Fergusion J. W. , Y. Q. Wu

Abundance analysis of carbon has been performed in a sample of 80 late F and early G type dwarf stars in the metallicity range -1.06 < [Fe/H] < 0.26 using the forbidden [C I] line at 8727 A. This line is presumably less sensitive to…

Astrophysics · Physics 2011-05-23 B. Gustafsson , T. Karlsson , E. Olsson , B. Edvardsson , N. Ryde

New information on the relations between the Galactic disks, the halo, and satellite galaxies is being obtained from elemental abundances of stars having metallicities in the range -1.5 < [Fe/H] < -0.5. The first results for a sample of 26…

Astrophysics · Physics 2015-05-13 Poul E. Nissen , William J. Schuster

The Galactic stellar halo is predicted to have formed at least partially from the tidal disruption of accreted dwarf galaxies. This assembly history should be detectable in the orbital and chemical properties of stars. The H3 Survey is…

We derive a star catalogue generated from the images taken as part of the 37.5 sq. deg Millennium Galaxy Catalogue. These data, alone and together with colours gained from the Sloan Digital Sky Survey Early Data Release, allow the analysis…

Astrophysics · Physics 2009-11-10 David Lemon , Rosemary F. G. Wyse , Jochen Liske , Simon Driver , Keith Horne

This paper focuses on carbon that is one of the most abundant elements in the Universe and is of high importance in the field of nucleosynthesis and galactic and stellar evolution. Even nowadays, the origin of carbon and the relative…

We review Galactic halo formation theories and supporting evidence, in particular kinematics and detailed chemical abundances of stars in some relevant globular clusters as well as Local Group dwarf galaxies. Outer halo red HB clusters tend…

Astrophysics · Physics 2009-11-13 Doug Geisler , George Wallerstein , Verne V. Smith , Dana I. Casetti-Dinescu
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