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相关论文: The origin of diverse $\alpha$-element abundances …

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The mean alpha-to-iron abundance ratio ([$\alpha$/Fe]) of galaxies is sensitive to the chemical evolution processes at early time, and it is an indicator of star formation timescale ($\tau_{{\rm SF}}$). Although the physical reason remains…

星系天体物理 · 物理学 2016-10-05 Yiqing Liu , Luis C. Ho , Eric Peng

We combine stellar orbits with the abundances of the heavy, $r$-process element europium and the light, $\alpha$-element, silicon to separate in-situ and accreted populations in the Milky Way across all metallicities. At high orbital…

We present a detailed study of the chemical diversity of the metal-poor Milky Way (MW) using data from the GALAH DR3 survey. Considering 17 chemical abundances relative to iron ([X/Fe]) for 9,923 stars, we employ Principal Component…

星系天体物理 · 物理学 2024-07-29 Nicole Buckley , Payel Das , Paula Jofré , Robert M. Yates , Keith Hawkins

Abundances for alpha-elements and Fe in about 150 field subdwarfs and early subgiants with accurate parallaxes and kinematic data are used to discuss the run of abundance ratios in metal-poor stars in the solar neighborhood. Based on…

Recent spectroscopic observations in the Milky Way suggest that the chemically defined thick disk (stars with high [alpha/Fe] ratios and thus old) has a significantly smaller scale-length than the thin disk. This is in apparent…

星系天体物理 · 物理学 2015-06-24 I. Minchev , M. Martig , D. Streich , C. Scannapieco , R. S. de Jong , M. Steinmetz

The ratio of $\alpha$-elements to iron in galaxies holds valuable information about the star formation history since their enrichment occurs on different timescales. The fossil record of stars in galaxies has mostly been excavated for…

星系天体物理 · 物理学 2022-01-19 Andrea Gebek , Jorryt Matthee

In order to understand the roles of metal flows in galaxy formation and evolution, we analyse our self-consistent cosmological chemo-dynamical simulation of a Milky Way like galaxy during its thin-disc phase. Our simulated galaxy disc…

星系天体物理 · 物理学 2020-06-03 Fiorenzo Vincenzo , Chiaki Kobayashi

[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…

天体物理学 · 物理学 2008-11-26 Andreea S. Font , Kathryn V. Johnston , James S. Bullock , Brant E. Robertson

We study the role of radial motions of stars and gas on the evolution of abundance profiles in the Milky Way disk. We investigate, in a parametrized way, the impact of radial flows of gas and radial migration of stars induced mainly by the…

星系天体物理 · 物理学 2015-08-19 M. Kubryk , N. Prantzos , E. Athanassoula

Stellar and supernova nucleosynthesis in the first few billion years of the cosmic history have set the scene for early structure formation in the Universe, while little is known about their nature. Making use of stellar physical parameters…

This paper focuses on carbon that is one of the most abundant elements in the Universe and is of high importance in the field of nucleosynthesis and galactic and stellar evolution. Even nowadays, the origin of carbon and the relative…

We study the origin of the wide distribution of angles between the angular momenta of the stellar and gas components, $\alpha_{\rm G,S}$, in early-type galaxies (ETGs). We use the GALFORM model of galaxy formation, set in the $\Lambda$ cold…

The disk components of galaxies generally show an exponential profile extending over several scale lengths, both in mass and star-formation rate, but the physical origin is not well understood. We explore a physical model in which the…

星系天体物理 · 物理学 2022-03-30 Enci Wang , Simon J. Lilly

We analyse for the first time the radial abundance gradients of the disc stars of a disc galaxy simulated with our three dimensional, fully cosmological chemodynamical galaxy evolution code GCD+. We study how [Fe/H], [N/O], [O/Fe], [Mg/Fe]…

星系天体物理 · 物理学 2015-05-27 Awat Rahimi , Daisuke Kawata , Carlos Allende Prieto , Chris B. Brook , Brad K. Gibson , Alina Kiessling

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…

星系天体物理 · 物理学 2015-06-03 Takuji Tsujimoto , Kenji Bekki

Stellar populations and their distribution differ widely across the Galaxy, which is likely to affect planet demographics. Our local neighbourhood is dominated by young, metal-rich stars in the galactic thin disc, while the stellar halo and…

地球与行星天体物理 · 物理学 2024-06-12 C. Boettner , P. Dayal , M. Trebitsch , N. Libeskind , K. Rice , C. Cockell , B. I. Tieleman

A linear [Fe/H]-[O/H] relation is found for different stellar populations in the Galaxy (halo, thick disk, thin disk) from a data sample obtained in a recent investigation (Ram{\'\i}rez et al. 2013). These correlations support previous…

星系天体物理 · 物理学 2017-06-15 R. Caimmi

Sulfur is a volatile chemical element that plays an important role in tracing the chemical evolution of galaxies. However, its nucleosynthesis origin and abundance variations are still unclear. The goal of the present article is to…

The inner Galaxy is the most complex region of the Milky Way, comprising the bulge, inner thin and thick discs, and inner halo; the formation of the bar transferred gas and stars from the disc inward. Accretion of dwarf galaxies also…

The evolution of C and O abundances in the Milky Way can impose strong constraints on stellar nucleosynthesis and help understanding the formation and evolution of our Galaxy. The aim is to review the measured C and O abundances in the disk…

星系天体物理 · 物理学 2015-05-13 G. Cescutti , F. Matteucci , A. McWilliam , C. Chiappini