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Related papers: Evidence for Halo Kinematics among Cool Carbon-Ric…

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This paper reports a Galactic kinematical and dynamical analysis of 1003 main-sequence carbon stars. The sample is drawn from the Sloan Digital Sky Survey, and cross-matched with Gaia DR3 to obtain 6-dimensional positions and velocities…

Solar and Stellar Astrophysics · Physics 2025-09-09 Jay Farihi , Jason L. Sanders , Sophia Lilleengen , Lewis J. Whitehouse , Denis Erkal

We present the kinematics of a sample of 398 DA white dwarfs from the SPY project (ESO SN Ia Progenitor surveY) and discuss kinematic criteria for distinguishing thin-disk, thick-disk, and halo populations. This is the largest homogeneous…

Astrophysics · Physics 2009-11-11 E. -M. Pauli , R. Napiwotzki , U. Heber , M. Altmann , M. Odenkirchen

Thanks to the recent space-borne mission Gaia, there is a nearly complete sample of white dwarfs up to about 100 parsecs from the Sun, which may have very diverse origins. We aim to compute the Galactic orbits for white dwarfs observed in…

Solar and Stellar Astrophysics · Physics 2024-07-24 Ainhoa Zubiaur , Roberto Raddi , Santiago Torres

The majority of hot subdwarf stars are low-mass core-helium-burning stars. Their atmospheres are generally helium deficient; however a minority have extremely helium-rich surfaces. An additional fraction have an intermediate surface-helium…

Solar and Stellar Astrophysics · Physics 2017-04-12 P. Martin , C. S. Jeffery , Naslim N. , V. M. Woolf

We have analysed the kinematics of a sample of 114 hot subdwarf stars, for 2/3 of which we present new proper motions, spectroscopic and photometric data. The vast majority of the stars show a kinematic behaviour that is similar to that of…

Astrophysics · Physics 2008-11-26 M. Altmann , H. Edelmann , K. S. de Boer

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

We present an analysis of the space motions of 742 subdwarf stars based on the sample of Carney et al. (1994, CLLA). Hipparcos parallaxes, TYC2+HIP proper motions and Tycho2 proper motions were combined with radial velocities and…

Astrophysics · Physics 2009-11-10 M. I. Arifyanto , B. Fuchs , H. Jahreiss , R. Wielen

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

We present kinematics of a sample of 107 DA white dwarfs from the SPY project and discuss kinematic criteria for a distinction of thin disk, thick disk, and halo populations. This is the first homogeneous sample of white dwarfs for which 3D…

Astrophysics · Physics 2009-11-07 E. -M. Pauli , R. Napiwotzki , M. Altmann , U. Heber , M. Odenkirchen , F. Kerber

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

We present the first detailed 3D kinematic analysis of a sample of 3133 white dwarfs that use Gaia astrometry plus radial velocities, which were measured either by Gaia or by ground based spectroscopic observations. The sample includes…

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

We present kinematics of a sample of 398 DA white dwarfs from the SPY project (ESO SN Ia Progenitor surveY) and discuss kinematic criteria for a distinction of thin disk, thick disk, and halo populations. This is the largest homogeneous…

Astrophysics · Physics 2007-05-23 E-M. Pauli , U. Heber , R. Napiwotzki , M. Altmann , M. Odenkirchen

A detailed analysis of halo white dwarf candidates is presented, which is based on model atmosphere fits to observed energy distributions built from photoelectric or photographic magnitudes. Most of the candidates identified in reduced…

Astrophysics · Physics 2009-11-07 P. Bergeron

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

We present the discovery and spectroscopic identification of two very high proper motion ancient white dwarf stars, found in a systematic proper motion survey. Their kinematics and apparent magnitude clearly indicate that they are halo…

Astrophysics · Physics 2009-10-31 Rodrigo Ibata , Michael Irwin , Olivier Bienayme , Ralf Scholz , Jean Guibert

We present a progress report on the kinematical analysis of the entire SPY (ESO SN Ia Progenitor surveY) sample of about one thousand white dwarfs and hot subdwarfs. In a previous study (Pauli et al. 2003, 2006) 398 DA white dwarfs have…

Astrophysics · Physics 2007-05-23 R. Richter , U. Heber , R. Napiwotzki

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

The kinematics of 122 red giants and 124 RR Lyrae variables in the solar neighborhood is studied using accurate measurements of their proper motions by the Hipparcos astrometry satellite, combined with the published photometric distances,…

Astrophysics · Physics 2009-10-30 Masashi Chiba , Yuzuru Yoshii
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