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

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We demonstrate that in N-body simulations of isolated disc galaxies there is numerical vertical heating which slowly increases the vertical velocity dispersion and the disc thickness. Even for models with over a million particles in a disc,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 S. A. Rodionov , N. Ya. Sotnikova

We analyze age-velocity dispersion relations (AVRs) from kinematics of individual stars in eight Local Group galaxies ranging in mass from Carina ($M_{*} \sim 10^{6}$) to M31 ($M_{*} \sim 10^{11}$). Observationally the $\sigma$ vs. stellar…

Vertically extended, high velocity dispersion stellar distributions appear to be a ubiquitous feature of disc galaxies, and both internal and external mechanisms have been proposed to be the major driver of their formation. However, it is…

The disk galaxy simulated using our chemo-dynamical galaxy formation code, GCD+, is shown to have a thick disk component. This is evidenced by the velocity dispersion versus age relation for solar neighbourhood stars, which clearly shows an…

Astrophysics · Physics 2009-11-10 Chris B. Brook , Daisuke Kawata , Brad K. Gibson , Ken C. Freeman

The stellar kinematics of the Galactic disk are main factors for constraining disk formation and evolution processes in the Milky Way (MW) Galaxy. In this paper we investigate a statistical relation between stellar Mass, Age and Velocity…

Astrophysics of Galaxies · Physics 2023-03-15 Hossein Fatheddin , Sedighe Sajadian

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…

Astrophysics · Physics 2009-11-13 J. Holmberg , B. Nordstrom , J. Andersen

New ages are computed for stars in the Solar Neighbourhood from the Edvardsson et al. (1993) data set. Distances derived from the Hipparcos parallaxes were adopted to obtain reliable ages (uncertainty less than 12%) for a subset of stars.…

Astrophysics · Physics 2007-05-23 Y. K. Ng , G. Bertelli , G. Carraro , L. Portinari

Most studies of correlations between X-ray and optical properties of galaxy clusters have used the largest samples of data available, regardless of the morphological types of clusters included. Given the increasing evidence that morphology…

Astrophysics · Physics 2009-10-28 Christina M. Bird , Richard F. Mushotzky , Christopher A. Metzler

We study the growth of stellar discs of Milky Way-sized galaxies using a suite of cosmological simulations. We calculate the half-mass axis lengths and axis ratios of stellar populations split by age in isolated galaxies with stellar mass…

Astrophysics of Galaxies · Physics 2022-08-16 Xi Meng , Oleg Y. Gnedin

Observations of disk galaxies at z~2 have demonstrated that turbulence driven by gravitational instability can dominate the energetics of the disk. We present a 1D simulation code, which we have made publicly available, that economically…

Astrophysics of Galaxies · Physics 2015-06-03 John Forbes , Mark R. Krumholz , Andreas Burkert

We present evidence that isolated growing discs, subject to internal spiral perturbations, thicken due to both heating \emph{and} radial migration. We show this by demonstrating that the thickness and vertical velocity dispersions of coeval…

Astrophysics of Galaxies · Physics 2015-06-12 Rok Roškar , Victor P. Debattista , Sarah R. Loebman

Our study aims to investigate the outer disc structure of the Milky Way galaxy using the red clump (RC) stars. We analysed the distribution of the largest sample of RC stars to date, homogeneously covering the entire Galactic plane in the…

Astrophysics of Galaxies · Physics 2023-11-17 Namita Uppal , Shashikiran Ganesh , Mathias Schultheis

The size-velocity dispersion ($\sigma$) relation, while well established for giant HII regions, remains uncertain for their smaller counterparts (physical radii R < 20 pc). Thanks to the LAMOST MRS-N dataset's large sky coverage and high…

We explore the heating of the velocity distribution in the solar neighbourhood by stochastic spiral waves. Our investigation is based on direct numerical integration of initially circular test-particle orbits in the sheared sheet. We…

Astrophysics · Physics 2009-11-10 Richard S. De Simone , Xiaoan Wu , Scott Tremaine

Using a new algorithm for estimating the actions of orbits a parametrised distribution function is automatically fitted to observational data for the solar neighbourhood. We adopt a gravitational potential that is generated by three discs…

Astrophysics of Galaxies · Physics 2015-06-05 James Binney

We study the kinematics of a local sample of stars, located within a cylinder of 500 pc radius centered on the Sun, in the RAVE dataset. We find clear asymmetries in the $v_R$-$v_\phi$ velocity distributions of thin and thick disk stars:…

The processes driving the formation and evolution of late-type galaxies (LTGs) continue to be a debated subject in extragalactic astronomy. Investigating stellar kinematics, especially when combined with age estimates, provides crucial…

It has long been known that the vertical motions of Galactic disk stars increase with stellar age, commonly interpreted as vertical heating through orbit scattering. Here we map the vertical actions of disk stars as a function of age…

Astrophysics of Galaxies · Physics 2019-06-19 Yuan-Sen Ting , Hans-Walter Rix

The dependences of the velocity ellipsoids of F-G stars of the thin disk of the Galaxy on their ages and metallicities are analyzed based on the new version of the Geneva-Copenhagen Catalog. The age dependences of the major, middle, and…

Astrophysics of Galaxies · Physics 2015-05-13 V. V. Koval' , V. A. Marsakov , T. V. Borkova

Within disk galaxies, the velocity dispersion, $\sigma$, of stars increases with age, $\tau$, as measured in the Milky Way (MW) and nearby galaxies. This relation provides a key window into galactic formation history, tracing both the…

Astrophysics of Galaxies · Physics 2025-06-16 Fiona McCluskey , Andrew Wetzel , Sarah Loebman , Jorge Moreno