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Related papers: The stellar population structure of the Galactic d…

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It is well established that the chemical structure of the Milky Way exhibits a bimodality with respect to the $\alpha$-enhancement of stars at a given [Fe/H]. This has been studied largely based on a bulk $\alpha$ abundance, computed as a…

Astrophysics of Galaxies · Physics 2019-09-20 Kirsten Blancato , Melissa Ness , Kathryn V. Johnston , Jan Rybizki , Megan Bedell

We present a brief summary of our current results on the stellar distribution and population gradients of the resolved stars in the surroundings of ~50 nearby disk galaxies, observed with space- (Hubble & Spitzer) and ground-based…

[Abridged] Ensemble studies of red-giant stars with exquisite asteroseismic, spectroscopic, and astrometric constraints offer a novel opportunity to recast and address long-standing questions concerning the evolution of stars and of the…

We present a model for the [alpha/Fe]-[Fe/H] distribution of stars in the inner Galaxy, R=3-5 kpc, measured as a function of vertical distance |z| from the midplane by Hayden et al. (2015, H15). Motivated by an "upside-down" scenario for…

Astrophysics of Galaxies · Physics 2017-11-01 Jenna K. C. Freudenburg , David H. Weinberg , Michael R. Hayden , Jon A. Holtzman

There is a long-standing debate on the origin of the metal-poor stellar populations of the Milky Way (MW) bulge, with the two leading scenarios being that these populations are either i) part of a classical metal-poor spheroid or ii) the…

Astrophysics of Galaxies · Physics 2018-09-12 F. Fragkoudi , P. Di Matteo , M. Haywood , M. Schultheis , S Khoperskov , A. Gómez , F. Combes

Stellar radial migration plays an important role in reshaping a galaxy's structure and the radial distribution of stellar population properties. In this work, we revisit reported observational evidence for radial migration and quantify its…

We derive age-metallicity relations (AMRs) and orbital parameters for the 1658 solar neighbourhood stars to which accurate distances are measured by the HIPPARCOS satellite. The sample stars comprise 1382 thin disc stars, 229 thick disc…

Astrophysics · Physics 2009-11-07 A. Ibukiyama , N. Arimoto

The formation of our Milky Way can be parsed qualitatively into different phases that resulted in its structurally different stellar populations: the halo and the disk components. Revealing a quantitative overall picture of the Galactic…

Astrophysics of Galaxies · Physics 2022-03-24 Maosheng Xiang , Hans-Walter Rix

We investigate, using the Gaia-ESO Survey internal Data-Release 2, the properties of the double sequence of the Milky Way discs (defined chemically as the high-alpha and low-alpha populations), and discuss their compatibility with discs…

We study the stellar population history and chemical evolution of the Milky Way (MW) in a hierarchical LCDM model for structure formation. Using a Monte Carlo method based on the semi-analytical EPS formalism, we reconstruct the merger tree…

Astrophysics · Physics 2008-11-26 S. Salvadori , R. Schneider , A. Ferrara

To disentangle the different competing physical processes at play in Galactic evolution, a detailed chrono chemicalkinematical, and dynamical characterisation of the disc bimodality is necessary, including high number statistics. Here we…

Astrophysics of Galaxies · Physics 2024-12-18 Alejandra Recio-Blanco , P. de Laverny , P. A. Palicio , S. Cassisi , A. Pietrinferni , N. Lagarde , C. Navarrete

Context. The [Mg/Fe] abundance ratios are a fundamental fossil signature to trace the chemical evolution of the disc. Despite of the huge observational and theoretical effort, discrepancies between models and data are still present and…

Astrophysics of Galaxies · Physics 2022-07-20 Marco Palla , Pablo Santos-Peral , Alejandra Recio-Blanco , Francesca Matteucci

We present an exploration of the Milky Way's structural parameters using an all-sky sample of RC giants to map the stellar density from the Galactic disc beyond 3 kpc. These evolved giants are considered to be standard candles due to their…

The radial metallicity distribution of the Milky Way's disc is an important observational constraint for models of the formation and evolution of our Galaxy. It informs our understanding of the chemical enrichment of the Galactic disc and…

We aim to quantify the chemical and kinematical properties of the Galactic disks with a sample of 119,558 giant stars having abundances and 3D velocities taken or derived from the APOGEE DR17 and Gaia EDR3 catalogs. The Gaussian Mixture…

Astrophysics of Galaxies · Physics 2022-04-20 Guozhen Hu , Zhengyi Shao

In some scenarios for the formation of the Milky Way bulge the stellar population at the edges of the boxy bulge may be younger than those on the minor axis, or close to the Galactic center. So far the only bulge region where deep…

Astrophysics of Galaxies · Physics 2015-06-17 E. Valenti , M. Zoccali , A. Renzini , T. M. Brown , O. Gonzalez , D. Minniti , Victor P. Debattista , L. Mayer

Open Clusters have long been used to study the chemo-dynamical evolution of the Galactic disk. This requires an homogeneously analysed sample covering a wide range of ages and distances. In this aper we present the OCCASO second data…

We present {complexity} of the Galactic outer disc {by fitting the stellar volume densities of the red giant branch stars with a two-disc component model}. {The discs are confirmed to} extend to $R\sim19$\,kpc. The radial density profile of…

Astrophysics of Galaxies · Physics 2018-07-04 Hai-Feng Wang , Chao Liu , Yan Xu , Jun-Chen Wan , Licai Deng

We study the kinematics of the Galactic thin and thick disk populations using stars from the RAVE survey's second data release together with distance estimates from Breddels et al. (2009). The velocity distribution exhibits the expected…

Astrophysics of Galaxies · Physics 2015-05-27 Yüksel Karatas , Rainer J. Klement

We map the trends of elemental abundance ratios across the Galactic disk, spanning R = 3-15 kpc and midplane distance |Z|= 0-2 kpc, for 15 elements in a sample of 20,485 stars measured by the SDSS/APOGEE survey (O, Na, Mg, Al, Si, P, S, K,…