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Vertical distribution of Galactic disk stars IV - AMR and AVR from clump giants
- Source :
- Astronomy and Astrophysics-A&A, Astronomy and Astrophysics-A&A, EDP Sciences, 2008, 480, pp.91-101. ⟨10.1051/0004-6361:20078788⟩
- Publication Year :
- 2008
- Publisher :
- HAL CCSD, 2008.
-
Abstract
- We present the parameters of 891 stars, mostly clump giants, including atmospheric parameters, distances, absolute magnitudes, spatial velocities, galactic orbits and ages. One part of this sample consists of local giants, within 100 pc, with atmospheric parameters either estimated from our spectroscopic observations at high resolution and high signal-to-noise ratio, or retrieved from the literature. The other part of the sample includes 523 distant stars, which we have estimated atmospheric parameters from high resolution but low signal-to-noise Echelle spectra. This new sample is kinematically unbiased, with well-defined boundaries in magnitude and colours. We revisit the basic properties of the Galactic thin disk as traced by clump giants. We find the metallicity distribution to be different from that of dwarfs, with less metal-rich stars. We find evidence for a vertical metallicity gradient of -0.31 dex/kpc and for a transition at 4-5 Gyr in both the metallicity and velocities. The age - metallicity relation (AMR), which exhibits a very low dispersion, increases smoothly from 10 to 4 Gyr, with a steeper increase for younger stars. The age-velocity relation (AVR) is characterized by the saturation of the V and W dispersions at 5 Gyr, and continuous heating in U.<br />Comment: 13 pages, 14 figures, accepted in A&A
- Subjects :
- Metallicity
FOS: Physical sciences
High resolution
Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
01 natural sciences
Spectral line
Galaxy: disk
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
0103 physical sciences
Stars: kinematics
Astrophysics::Solar and Stellar Astrophysics
Disc
010303 astronomy & astrophysics
Galaxy: structure
Astrophysics::Galaxy Astrophysics
Stars: fundamental parameters
Physics
[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]
010308 nuclear & particles physics
Astrophysics (astro-ph)
Astronomy and Astrophysics
Stars
Thin disk
13. Climate action
Space and Planetary Science
Astrophysics::Earth and Planetary Astrophysics
Solar neighbourhood
Subjects
Details
- Language :
- English
- ISSN :
- 00046361
- Database :
- OpenAIRE
- Journal :
- Astronomy and Astrophysics-A&A, Astronomy and Astrophysics-A&A, EDP Sciences, 2008, 480, pp.91-101. ⟨10.1051/0004-6361:20078788⟩
- Accession number :
- edsair.doi.dedup.....295940ba12c9685fddea58059c1fb166
- Full Text :
- https://doi.org/10.1051/0004-6361:20078788⟩