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

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Stellar ages are a crucial component to studying the evolution of the Milky Way. Using Gaia DR2 distance estimates, it is now possible to estimate stellar ages for a larger volume of evolved stars through isochrone matching. This work…

The chemical evolution of the Milky Way is investigated using a dual-phase metal-enriched infall model in which primordial gas fuels the earliest epoch of star formation, followed by the ongoing formation of stars from newly accreted gas.…

Astrophysics · Physics 2009-11-07 Yeshe Fenner , Brad K. Gibson

Standard chemical evolution models based on long-term infall are affected by a number of problems, evidenced by the analysis of the most recent data. Among these: (1) models rely on the local metallicity distribution, assuming its shape is…

Astrophysics of Galaxies · Physics 2014-01-10 Misha Haywood

We use recently derived ages for 61 Milky Way (MW) globular clusters (GCs) to show that their age-metallicity relation (AMR) can be divided into two distinct, parallel sequences at [Fe/H] $\ga -1.8$. Approximately one-third of the clusters…

Astrophysics of Galaxies · Physics 2015-06-17 Ryan Leaman , Don A. VandenBerg , J. Trevor Mendel

The metal-poor stars of a galaxy offer insights into that galaxy's early formation processes and accretion history. Here, we investigate whether the metal-poor stars of our Milky Way galaxy exhibit any characteristic trends in…

Astrophysics of Galaxies · Physics 2025-08-13 Khyati Malhan

Results of recent observations of the Galactic bulge demand that we discard a simple picture of its formation, suggesting the presence of two stellar populations represented by two peaks of stellar metallicity distribution (MDF) in the…

Astrophysics of Galaxies · Physics 2015-06-03 Takuji Tsujimoto , Kenji Bekki

The manner the galaxy accretes matter along with the star formation rates at different epochs, influence the evolution of the stable isotopic inventories of the galaxy. A detailed analysis is presented here to study the dependence of the…

Astrophysics of Galaxies · Physics 2014-08-05 S. Sahijpal

We present the results of our investigation of three samples kinematically representative of the thin and thick disks and the Hercules stream using the catalogue of Soubiran & Girard (2005). We have observed abundance trends and age…

Astrophysics · Physics 2009-07-10 Pascal Girard , Caroline Soubiran

Metallicities of both gas and stars decline toward large radii in spiral galaxies, a trend known as the radial metallicity gradient. We quantify the evolution of the metallicity gradient in the Milky Way as traced by APOGEE red giants with…

Recent work has produced a wealth of data concerning the chemical evolution of the galactic bulge, both for stars and nebulae. Present theoretical models generally adopt a limited range of such constraints, frequently using a single…

Astrophysics of Galaxies · Physics 2009-01-29 R. D. D. Costa , W. J. Maciel , A. V. Escudero

[Abridged] In this first paper of this series, we present a new approach for studying the chemo-dynamical evolution in disk galaxies, which consists of fusing disk chemical evolution models with compatible numerical simulations of galactic…

Astrophysics of Galaxies · Physics 2015-06-11 I. Minchev , C. Chiappini , M. Martig

The proto-Milky Way epoch forms the earliest stars in our Galaxy and sets the initial conditions for subsequent disk formation. Recent observations from APOGEE and H3 surveys showed that the [$\alpha$/Fe] ratio slowly declined between…

Astrophysics of Galaxies · Physics 2024-11-11 Boquan Chen , Yuan-Sen Ting , Michael Hayden

The formation of galaxies can be understood in terms of the assembly patterns of each type of galactic component. To perform this kind of analysis, is necessary to define some criteria to separate those components. Decomposition methods…

Many nucleosynthetic channels create the elements, but two-parameter models characterized by $\alpha$ and Fe nonetheless predict stellar abundances in the Galactic disk to accuracies of 0.02 to 0.05 dex for most measured elements, near the…

[Abridged] Motivated by upcoming data from astrometric and spectroscopic surveys of the Galaxy, we explore the chemical abundance properties and phase-space distributions in hierarchically-formed stellar halo simulations set in a LambdaCDM…

Astrophysics · Physics 2008-11-26 Andreea S. Font , Kathryn V. Johnston , James S. Bullock , Brant E. Robertson

The star formation rate history of the Milky Way is derived using the chromospheric age distribution for 552 stars in the solar neighborhood. The stars sample birthsites distributed over a very large range of distances because of orbital…

Astrophysics · Physics 2009-10-31 Helio J. Rocha-Pinto , John Scalo , Walter Maciel , Chris Flynn

Despite the recent advancements in the field of galaxy formation and evolution, fully self-consistent simulations are still unable to make the detailed predictions necessary for the planned and ongoing large spectroscopic and photometry…

Astrophysics of Galaxies · Physics 2019-08-19 Ivan Minchev , Cristina Chiappini , Marie Martig

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…

ABRIDGED: METHODS: We have conducted a high-resolution spectroscopic study of 714 F and G dwarf and subgiant stars in the Solar neighbourhood. The star sample has been kinematically selected to trace the Galactic thin and thick disks to…

Astrophysics of Galaxies · Physics 2015-06-17 T. Bensby , S. Feltzing , M. S. Oey

We present theoretical results on the galactic abundance gradients of several chemical species for the Milky Way disk, obtained using an improved version of the two-infall model of Chiappini, Matteucci, & Gratton (1997) that incorporates a…

Astrophysics · Physics 2007-05-23 Cristina Chiappini , Francesca Matteucci , Donatella Romano