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相关论文: Local stellar kinematics from RAVE data: IV. Solar…

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We investigate radial metallicity gradients for a sample of dwarf stars from the RAdial Velocity Experiment (RAVE) Data Release 3 (DR3). We select a total of approximately 17000 F-type and G-type dwarfs using selection of colour, log g, and…

星系天体物理 · 物理学 2015-05-30 B. Coskunoglu , S. Ak , S. Bilir , S. Karaali , O. Onal , E. Yaz , G. Gilmore , G. M. Seabroke

We present and discuss new determinations of metallicity, rotation, age, kinematics, and Galactic orbits for a complete, magnitude-limited, and kinematically unbiased sample of 16,682 nearby F and G dwarf stars. Our 63,000 new, accurate…

天体物理学 · 物理学 2009-07-09 B. Nordstrom , M. Mayor , J. Andersen , J. Holmberg , F. Pont , B. R. Jorgensen , E. H. Olsen , S. Udry , N. Mowlavi

We present the detailed spectroscopic analysis of 72 evolved stars, including the [Fe/H] determination for the whole sample. These metallicities, together with the Teff values and the absolute V magnitude derived from Hipparcos parallaxes,…

We derive stellar ages, from evolutionary tracks, and metallicities, from Stromgren photometry, for a sample of 5828 dwarf and sub-dwarf stars from the Hipparcos Catalogue. This stellar disk sample is used to investigate the age-metallicity…

天体物理学 · 物理学 2009-11-07 Sofia Feltzing , Johan Holmberg , Jarrod R. Hurley

A new metallicity distribution and an age-metallicity relation are presented for 437 nearby F and G turn-off and sub-giant stars selected from radial velocity data of Nidever et al. Photometric metallicities are derived from uvby-H\beta…

天体物理学 · 物理学 2009-11-11 Y. Karatas , S. Bilir , W. J. Schuster

The age-metallicity relation for F and G dwarf stars in the solar neighborhood, based on the stellar metallicity data of Edvardsson et al. (1993), shows an apparent scatter that is larger than expected considering the uncertainties in…

天体物理学 · 物理学 2009-10-31 D. R. Garnett , H. A. Kobulnicky

A new method is presented to compute age estimates from theoretical isochrones using temperature, luminosity and metallicity data for individual stars. Based on Bayesian probability theory, this method avoids the systematic biases affecting…

天体物理学 · 物理学 2009-11-10 Frederic Pont , Laurent Eyer

The age-metallicity relation is a fundamental tool for constraining the chemical evolution of the Galactic disc. In this work we analyse the observational properties of this relation using binary stars that have not interacted consisting of…

We explore the connections between stellar age, chemistry, and kinematics across a Galactocentric distance of $7.5 < R\,(\mathrm{kpc}) < 9.0$, using a sample of $\sim 12\,000$ intermediate-mass (FGK) turnoff stars observed with the RAdial…

The age-metallicity relation of the solar neighbourhood is studied using a sample of 552 late-type dwarfs. This sample was built from the intersection of photometric catalogues with chromospheric activity surveys of the Mount Wilson group.…

天体物理学 · 物理学 2007-05-23 H. J. Rocha-Pinto , W. J. Maciel , John Scalo , Chris Flynn

Ages, metallicities, space velocities, and Galactic orbits of stars in the Solar neighbourhood are fundamental observational constraints on models of galactic disk evolution. We aim to consolidate the calibrations of uvby photometry into…

天体物理学 · 物理学 2009-11-13 J. Holmberg , B. Nordstrom , J. Andersen

Age is the most difficult fundamental stellar parameter to infer for isolated stars. While isochrone-based ages are in general imprecise for both main sequence dwarfs and red giants, precise isochrone-based ages can be obtained for stars on…

太阳与恒星天体物理 · 物理学 2024-07-29 David M. Nataf , Kevin C. Schlaufman , Henrique Reggiani , Isabel Hahn

We investigate the vertical metallicity gradients of five mono-age stellar populations between 0 and 11 Gyr for a sample of 18 435 dwarf stars selected from the cross-matched Tycho-Gaia Astrometric Solution (TGAS) and RAdial Velocity…

星系天体物理 · 物理学 2018-01-16 Ioana Ciucă , Daisuke Kawata , Jane Lin , Luca Casagrande , George Seabroke , Mark Cropper

We examine the possibility of the inclusion of objects having lifetimes lower than the disk age in the database of recent determinations of the G dwarf metallicity distribution for the solar neighbourhood. As a preliminary step, stars with…

天体物理学 · 物理学 2007-05-23 Helio J. Rocha-Pinto , Walter J. Maciel

A comparison is made between the age-metallicity relation obtained from four different types of studies: F and G stars in the Solar Neighbourhood, analysis of open clusters, galactic structure studies with the stellar population synthesis…

天体物理学 · 物理学 2009-10-30 G. Carraro , Y. K. Ng , L. Portinari

We estimated iron and metallicity gradients in the radial and vertical directions with the F and G type dwarfs taken from the RAVE DR4 database. The sample defined by the constraints Zmax<=825 pc and ep<=0.10 consists of stars with metal…

星系天体物理 · 物理学 2015-11-18 O. Plevne , T. Ak , S. Karaali , S. Bilir , S. Ak , Z. F. Bostanci

Age-metallicity relation for the Galactic disc is a crucial tool and to constrain the Galactic chemical evolution models. We investigate the age-metallicity relation of the Galactic disc using the red giant branch stars in the Solar…

星系天体物理 · 物理学 2023-05-01 S. Doner , S. Ak , O. Onal Tas , O. Plevne

The ages of the oldest and most metal-poor stars in the Milky Way bear important information on the age of the Universe and its standard model. We analyze a sample of 28 extremely metal-poor field stars in the solar vicinity culled from the…

太阳与恒星天体物理 · 物理学 2022-12-07 Anastasiia Plotnikova , Giovanni Carraro , Sandro Villanova , Sergio Ortolani

We show that there is a relationship between the age excess, defined as the difference between the stellar isochrone and chromospheric ages, and the metallicity as measured by the index [Fe/H] for late-type dwarfs. The chromospheric age…

天体物理学 · 物理学 2016-08-30 H. J. Rocha-Pinto , W. J. Maciel

The chemical composition of Earth's atmosphere has undergone substantial evolution over the course of its history. It is possible, even likely, that terrestrial planets in other planetary systems have undergone similar changes;…

天体物理学 · 物理学 2009-06-23 I. Neill Reid , Edwin L. Turner , Margaret C. Turnbull , M. Mountain , Jeff A. Valenti
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