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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…

Using a sample of red giant stars from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) Data Release 16, we infer the conditional distribution $p([\alpha/\text{Fe}]\,|\,[\text{Fe/H}])$ in the Milky Way disk for the…

星系天体物理 · 物理学 2021-10-13 Fiorenzo Vincenzo , David H. Weinberg , Andrea Miglio , Richard R. Lane , Alexandre Roman-Lopes

The Milky Way hosts at least two modes in its present day distribution of Fe and alpha-elements. The exact cause of this bimodality is disputed, but one class of explanations involves the merger between the Milky Way and a relatively…

星系天体物理 · 物理学 2025-07-24 Angus Beane , James Johnson , Vadim Semenov , Lars Hernquist , Vedant Chandra , Charlie Conroy

Recent dynamical analysis based on Gaia data have revealed major accretion events in Milky Way's history. Nevertheless, our understanding of the primordial Galaxy is hindered because the bona fide identification of the most metal-poor and…

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…

星系天体物理 · 物理学 2025-02-26 Angus Beane

We explore the elemental abundance features of metal-rich disk stars, highlighting the comparisons made with those of the recently revealed Galactic bulge stars. A similarity between two of the comparisons leads to a new theoretical picture…

天体物理学 · 物理学 2009-11-13 Takuji Tsujimoto

The stellar disk of the Milky Way shows complex spatial and abundance structure that is central to understanding the key physical mechanisms responsible for shaping our Galaxy. In this study, we use six very high resolution cosmological…

We investigate stellar elemental abundance patterns at z = 0 in 8 low-mass (M_* = 10^6 - 10^9 M_sun) galaxies in the Feedback in Realistic Environments (FIRE-2) cosmological simulations. Using magnesium (Mg) as a representative…

The analysis of the APOGEE data suggests the existence of a clear distinction between two sequences of disc stars in the [$\alpha$/Fe] vs. [Fe/H] abundance ratio space. We aim to test if the two-infall chemical evolution models designed to…

星系天体物理 · 物理学 2022-08-03 E. Spitoni , V. Aguirre Børsen-Koch , K. Verma , A. Stokholm

A scenario for the formation of the bi-modality in the chemical space [$\alpha$/Fe] vs [Fe/H] of the Milky Way was recently proposed in which $\alpha$-enhanced stars are produced early and quickly in clumps. Besides accelerating the…

星系天体物理 · 物理学 2020-02-12 Leandro Beraldo e Silva , Victor P. Debattista , Tigran Khachaturyants , David Nidever

Theories of thick disk formation can be differentiated by measurements of stellar elemental abundances. We have undertaken a study of metal-poor stars selected from the RAVE spectroscopic survey of bright stars to establish whether or not…

In this paper, we study the formation and chemical evolution of the Milky Way disc with particular focus on the abundance patterns ([$\alpha$/Fe] vs. [Fe/H]) at different Galactocentric distances, the present-time abundance gradients along…

星系天体物理 · 物理学 2018-09-12 V. Grisoni , E. Spitoni , F. Matteucci

Using multi-element abundances from the SDSS APOGEE survey, we investigate the origin of abundance variations in Milky Way (MW) disk stars on the "high-$\alpha$ plateau," with $-0.5\leq\rm{[Mg/H]}\leq-0.1$ and…

星系天体物理 · 物理学 2025-09-25 Tawny Sit , David H. Weinberg , Emily J. Griffith

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…

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…

星系天体物理 · 物理学 2019-05-07 A. Rojas-Arriagada , M. Zoccali , M. Schultheis , A. Recio-Blanco , G. Zasowski , D. Minniti , H. Jönsson , R. E. Cohen

We analyse a set of very metal-poor stars for which accurate chemical abundances have been obtained as part of the ESO Large Program "First stars" in the light of the Gaia DR2 data. The kinematics and orbital properties of the stars in the…

星系天体物理 · 物理学 2020-04-29 P. Di Matteo , M. Spite , M. Haywood , P. Bonifacio , A. Gómez , F. Spite , E. Caffau

We explore the origin of the observed decline in [O/Fe] (and [Mg/Fe]) with Galactocentric distance for high-metallicity stars ([Fe/H] > -1.1), based on a sample of halo stars selected within the Apache Point Observatory Galactic Evolution…

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…

星系天体物理 · 物理学 2015-06-17 T. Bensby , S. Feltzing , M. S. Oey

The analysis of several spectroscopic surveys indicates the presence of a bimodality between the disc stars in the abundance ratio space of [${\alpha}$/Fe] versus [Fe/H]. The two stellar groups are commonly referred to as the…

星系天体物理 · 物理学 2024-10-09 E. Spitoni , F. Matteucci , R. Gratton , B. Ratcliffe , I. Minchev , G. Cescutti

The {\alpha}-element abundances of the globular cluster (GC) and field star populations of galaxies encode information about the formation of each of these components. We use the E-MOSAICS cosmological simulations of ~L* galaxies and their…