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Related papers: Challenges to the Two-Infall Scenario by Large Ste…

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We analyze the star formation history (SFH) of the Galactic disk by using an infall model. Based on the observed SFH of the Galactic disk, we first determine the timescales of the gas infall into the Galactic disk ($t_{\rm in}$) and that of…

Astrophysics · Physics 2009-10-31 T. T. Takeuchi , H. Hirashita

The separation of the Milky Way disk into a thin and thick component is supported by differences in the spatial, kinematic and metallicity distributions of their stars. These differences have led to the view that the thick disk formed early…

Astrophysics of Galaxies · Physics 2015-05-20 Sarah R. Loebman , Rok Roskar , Victor P. Debattista , Zeljko Ivezic , Thomas R. Quinn , James Wadsley

The elemental abundance distribution of stars encodes the history of the gas-phase abundance in the Milky Way. Without a large, unbiased sample of highly precise stellar ages, the exact timing and nature of this history must be inferred…

Astrophysics of Galaxies · Physics 2025-02-26 Angus Beane

The majority of chemical evolution models assume that the Galactic disk forms by means of infall of gas and divide the disk into several independent rings without exchange of matter between them. However, if gas infall is important, radial…

Astrophysics of Galaxies · Physics 2015-05-28 E. Spitoni , F. Matteucci

We quantify the inside-out growth of the Milky Way's low-alpha stellar disk, modelling the ages, metallicities and Galactocentric radii of APOGEE red clump stars with 6 < R < 13 kpc. The current stellar distribution differs significantly…

Astrophysics of Galaxies · Physics 2019-11-06 Neige Frankel , Jason Sanders , Hans-Walter Rix , Yuan-Sen Ting , Melissa Ness

A chromospheric age distribution of 552 late-type dwarfs is transformed into a star formation history by the application of scale height corrections, stellar evolutionary corrections and volume corrections. We show that the disk of our…

Astrophysics · Physics 2007-05-23 H. J. Rocha-Pinto , John Scalo , W. J. Maciel , Chris Flynn

We study the chemical properties of the stellar populations in eight simulations of the formation of Milky-Way mass galaxies in a LCDM Universe. Our simulations include metal-dependent cooling and an explicitly multiphase treatment of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Patricia B. Tissera , Simon D. M. White , Cecilia Scannapieco

We explore the structure of the element abundance--age--orbit distribution of the stars in the Milky Way's low-$\alpha$ disk, by (re-)deriving precise [Fe/H], [X/Fe] and ages, along with orbits, for red clump stars from the APOGEE survey.…

Solar and Stellar Astrophysics · Physics 2019-10-09 Melissa K. Ness , Kathryn V. Johnston , Kirsten Blancato , Hans-Walter Rix , Angus Beane , Jonathan C. Bird , Keith Hawkins

A major goal in the field of galaxy formation is to understand the formation of the Milky Way's disk. The first step toward doing this is to empirically describe its present state. We use the new high-dimensional dataset of 19 abundances…

Astrophysics of Galaxies · Physics 2020-02-19 Bridget L. Ratcliffe , Melissa K. Ness , Kathryn V. Johnston , Bodhisattva Sen

We compare abundance ratio trends in a sample of $\sim 11,000$ Milky Way bulge stars ($R_{\rm GC} < 3$ kpc) from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) to those of APOGEE stars in the Galactic disk ($5$ kpc $<…

The Galactic bulge has a bimodal metallicity distribution function: different kinematic, spatial, and, potentially, age distributions characterize the metal-poor and metal-rich components. Despite this observed dichotomy, which argues for…

Astrophysics of Galaxies · Physics 2019-05-07 A. Rojas-Arriagada , M. Zoccali , M. Schultheis , A. Recio-Blanco , G. Zasowski , D. Minniti , H. Jönsson , R. E. Cohen

In this work, we study the formation and chemical evolution of the Galactic bulge with particular focus on the abundance pattern ([Mg/Fe] vs. [Fe/H]), metallicity and age distribution functions. We consider detailed chemical evolution…

We aim at studying the abundance gradients along the Galactic disk and their dependence upon several parameters: a threshold in the surface gas density regulating star formation, the star formation efficiency, the timescale for the…

Astrophysics · Physics 2009-11-13 E. Colavitti , G. Cescutti , F. Matteucci , G. Murante

I review the uncertainties in two observational constraints of the Galactic disc chemical evolution: the metallicity distribution (MD) of long-lived dwarfs and the age-metallicity relation (AMR). It is shown first that the observed MD,…

Astrophysics · Physics 2009-11-11 M. Haywood

We study the formation of chemical sequences in the stellar disc of Milky Way (MW)-mass galaxies in a full cosmological context with the auriga simulations. We focus on the conditions giving rise to bi-modal $\alpha$-chemistry in the MW…

Astrophysics of Galaxies · Physics 2025-12-24 Matthew D. A. Orkney , Chervin F. P. Laporte , Robert J. J. Grand , Volker Springel

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

We study the chemical evolution and formation of the Galactic halo through the analysis of its stellar metallicity distribution function and some key elemental abundance patterns. Starting from the two-infall model for the Galaxy, which…

Astrophysics of Galaxies · Physics 2015-06-15 G. Brusadin , F. Matteucci , D. Romano

The Milky Way harbours two disks that appear distinct concerning scale-heights, kinematics, and elemental abundance patterns. Recent years have seen a surge of studies of the elemental abundance trends in the disks using high resolution…

Astrophysics · Physics 2007-05-23 Sofia Feltzing

Observations of the Milky Way's low-$\alpha$ disk show that at fixed metallicity, [Fe/H], several element abundance, [X/Fe], correlate with age, with unique slopes and small scatters around the age-[X/Fe] relations. In this study, we turn…

The recently emerging conviction that thick disks are prevalent in disk galaxies, and their seemingly ubiquitous old ages, means that the formation of the thick disk, perhaps more than any other component, holds the key to unravelling the…

Astrophysics · Physics 2009-11-10 Chris B. Brook , Brad K. Gibson , Hugo Martel , Daisuke Kawata
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