English
Related papers

Related papers: Kinematics of Nearby Subdwarf Stars

200 papers

A sample of subdwarfs with accurate space velocities and standarized metallicities is presented. This was constructed by combining Hipparcos parallaxes ond proper motions with radial velocities and metallicities from Carney et al. (1994;…

Astrophysics · Physics 2009-10-31 B. Fuchs , H. Jahreiss , R. Wielen

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

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 analyze a new kinematic survey that includes accurate proper motions derived from SDSS DR7 positions, combined with multi-epoch measurements from the GSC-II database. By means of the SDSS spectro-photometric data (effective temperature,…

Astrophysics of Galaxies · Physics 2015-05-18 A. Spagna , M. G. Lattanzi , P. Re Fiorentin , R. L. Smart

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

High resolution spectra of 5 candidate metal-weak thick-disc stars suggested by Beers & Sommer-Larsen (1995) are analyzed to determine their chemical abundances. The low abundance of all the objects has been confirmed with metallicity…

Astrophysics · Physics 2009-10-31 P. Bonifacio , M. Centurion , P. Molaro

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 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

Full space velocities are computed for a sample of 130 nearby RR Lyrae variables using both ground-based and Hipparcos proper motions. In many cases proper motions from multiple sources have been averaged to produce a significant…

Astrophysics · Physics 2009-10-30 John C. Martin , Heather L. Morrison

(Abbreviated) We present a detailed analysis of the space motions of 1203 solar-neighborhood stars with metal abundances [Fe/H] <= -0.6, on the basis of a recently revised and supplemented catalog of metal-poor stars selected without…

Astrophysics · Physics 2009-05-29 M. Chiba , T. C. Beers

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

An abundance analysis is presented of 60 metal-poor stars drawn from catalogues of nearby stars provided by Ariyanto et al. (2005) and Schuster et al. (2006). In an attempt to isolate a sample of metal-weak thick disc stars, we applied the…

Astrophysics · Physics 2009-11-13 Bacham E. Reddy , David L. Lambert

We present a kinematic analysis of a sample of 23,908 G- and K-type dwarfs in the Galactic disk. Based on the $\alpha$-abundance ratio, [$\alpha$/Fe], we separated our sample into low-$\alpha$ thin-disk and high-$\alpha$ thick-disk stars.…

Astrophysics of Galaxies · Physics 2020-06-17 Doo Ri Han , Young Sun Lee , Young Kwang Kim , Timothy C. Beers

Abundances for alpha-elements and Fe in about 150 field subdwarfs and early subgiants with accurate parallaxes and kinematic data are used to discuss the run of abundance ratios in metal-poor stars in the solar neighborhood. Based on…

Based on the LAMOST survey and Sloan Digital Sky Survey (SDSS), we use low-resolution spectra of 130,043 F/G-type dwarf stars to study the kinematics and metallicity properties of the Galactic disk. Our study shows that the stars with…

Astrophysics of Galaxies · Physics 2016-10-12 Yingjie Jing , Cuihua Du , Jiayin Gu , Yunpeng Jia , Xiyan Peng , Yuqin Chen , Zhenyu Wu , Jun Ma , Xu Zhou , Zihuang Cao , Yonghui Hou , Yuefei Wang , Yong Zhang

Data of our compiled catalog containing the positions, velocities, and metallicities of 415 RR~Lyrae variable stars and the relative abundances [el/Fe] of 12~elements for 101 RR~Lyrae stars, including four $\alpha$~elements (Mg, Ca, Si, and…

Astrophysics of Galaxies · Physics 2018-02-20 V. A. Marsakov , M. L. Gozha , V. V. Koval'

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

As an investigation of the origin of ``$\alpha$-poor'' halo stars, we analyze kinematic and abundance data for 73 intermediate metallicity stars ($-1 >$ [Fe/H] $\geq -2$) selected from Paper I of this series. We find evidence for a…

Astrophysics · Physics 2009-12-08 Jon P. Fulbright

Large numbers of low-to-medium resolution spectra of M-type dwarf stars from both the local Galactic disk and halo are available from various surveys. In order to fully exploit these data, we develop a template-fit method using a set of…

Solar and Stellar Astrophysics · Physics 2020-03-11 Neda Hejazi , Sebastien Lepine , Derek Homeier , R. Michael Rich , Michael M. Shara
‹ Prev 1 2 3 10 Next ›