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Related papers: Re-visiting the relations: Galactic thin disc age-…

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The velocity dispersion of nearby stars in the Galactic disc is well known to increase substantially with age; this is the so-called Age-Velocity relation, and is interpreted as a ``heating'' of the disc as a function of time. We have…

Astrophysics · Physics 2009-11-07 Jyrki Hanninen , Chris Flynn

The stellar velocity ellipsoid of the solar neighbour is re-examined using intermediate-old mono-abundances stellar groups with high quality chemistry data together with parallaxes and proper motions from Gaia DR1. We find the average…

Astrophysics of Galaxies · Physics 2017-12-20 Borja Anguiano , Steven R. Majewski , Kenneth C. Freeman , Arik W. Mitschang , Martin C. Smith

Warps are observed in a large fraction of disc galaxies, and can be due to a large number of different processes. Some of these processes might also cause vertical heating and flaring. Using a sample of galaxies simulated in their…

Astrophysics of Galaxies · Physics 2022-12-07 J. García de la Cruz , M. Martig , I. Minchev

The vertical density distribution of stars in a galactic disc is traditionally obtained by assuming an isothermal vertical velocity dispersion of stars. Recent observations from SDSS, LAMOST, RAVE, Gaia etc show that this dispersion…

Astrophysics of Galaxies · Physics 2020-12-04 Suchira Sarkar , Chanda J. Jog

Observations of stars in the the solar vicinity show a clear tendency for old stars to have larger velocity dispersions. This relation is called the age-velocity dispersion relation (AVR) and it is believed to provide insight into the…

Astrophysics of Galaxies · Physics 2017-03-29 Jun Kumamoto , Junichi Baba , Takayuki R. Saitoh

We explored a method to reconstruct the distribution function of the Galactic thick disc within the action space where nearby thick-disc stars are distributed. By applying this method to 127 chemically-selected thick-disc stars in the Solar…

Astrophysics of Galaxies · Physics 2015-09-30 Kohei Hattori , Gerard Gilmore

We study the relation between stellar ages and vertical velocity dispersion (the age-velocity relation, or AVR) in a sample of seven simulated disc galaxies. In our simulations, the shape of the AVR for stars younger than 9 Gyr depends…

Astrophysics of Galaxies · Physics 2014-08-05 Marie Martig , Ivan Minchev , Chris Flynn

We present the age-velocity dispersion relation (AVR) in three dimensions in the solar neighbourhood using 3,564 commonly observed sub-giant/red-giant branch stars selected from LAMOST, which gives the age and radial velocity, and…

Astrophysics of Galaxies · Physics 2018-01-31 Jincheng Yu , Chao Liu

We re-examine the age-velocity dispersion relation in the solar neighborhood using improved stellar age estimates that are based on Hipparcos parallaxes and recent stellar evolution calculations. The resulting relation shows that the Milky…

Astrophysics · Physics 2007-05-23 Alice C. Quillen , Donald R. Garnett

We analyse the heating of stellar discs by non axisymmetric structures and giant molecular clouds (GMCs) in N-body simulations of growing disc galaxies. The analysis resolves long-standing discrepancies between models and data by…

Astrophysics of Galaxies · Physics 2016-07-08 Michael Aumer , James Binney , Ralph Schönrich

We explore the fundamental relations governing the radial and vertical velocity dispersions of stars in the Milky Way, from combined studies of complementary surveys including GALAH, LAMOST, APOGEE, the NASA $Kepler$ and K2 missions, and…

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…

Astrophysics of Galaxies · Physics 2023-05-01 S. Doner , S. Ak , O. Onal Tas , O. Plevne

Using nearly 230,000 red clump (RC) stars selected from LAMOST and Gaia, we conduct a comprehensive analysis of the stellar age-velocity dispersion relations (AVRs) for various disk populations, within 5.0 $\leq$ $R$ $\leq$ 15.0 kpc and…

Astrophysics of Galaxies · Physics 2025-01-07 Weixiang Sun , Han Shen , Biwei Jiang , Xiaowei Liu

Understanding the history and the evolution of the Milky Way disc is one of the main goals of modern astrophysics. We study the velocity dispersion behaviour of Galactic disc stars as a function of the [Mg/Fe] ratio, which can be used as a…

We analyse the mechanisms ruling galactic disc heating through the dynamics of space velocities $U$, $V$ and $W$, extracted from the Geneva-Copenhagen catalogue. To do this, we use a model based on non-extensive statistical mechanics, where…

Solar and Stellar Astrophysics · Physics 2020-12-02 C. A. P. Viana , D. B. de Freitas

The velocity dispersions of stars near the Sun are known to increase with stellar age, but age can be difficult to determine so a proxy like the abundance of alpha elements (e.g., Mg) with respect to iron, [alpha/Fe], is used. Here we…

We study the self-consistent, linear response of a galactic disc to non-axisymmetric perturbations in the vertical direction as due to a tidal encounter, and show that the density distribution near the disc mid-plane has a strong impact on…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-18 Pratyush Pranav , Chanda J. Jog

In the solar-neighbourhood, older stars have larger random velocities than younger ones. It is argued that the increase in velocity dispersion with time is predominantly a gradual process rather than one induced by discrete events such as…

Astrophysics · Physics 2007-05-23 James Binney

In this paper, we investigate some chemokinematical properties of the Milky Way disk, by using a sample composed by 424 late-type dwarfs. We show that the velocity dispersion of a stellar group correlates with the age of this group,…

Astrophysics · Physics 2009-11-10 H. J. Rocha-Pinto , C. Flynn , J. Scalo , J. Hanninen , W. J. Maciel , G. Hensler

We present an evolutionary disc model for the thin disc in the solar cylinder based on a continuous star formation history and a continuous dynamical heating of the stellar subpopulations. The vertical distribution of the stellar…

Astrophysics · Physics 2016-04-26 A. Just , H. Jahreiss
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