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相关论文: Geometric properties of galactic discs with clumpy…

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Using idealised N-body simulations of a Milky Way-sized disc galaxy, we qualitatively study how the metallicity distributions of the thin disc star particles are modified by the formation of the bar and spiral arm structures. The thin disc…

星系天体物理 · 物理学 2016-09-21 D. Kawata , R. J. J. Grand , B. K. Gibson , L. Casagrande , J. A. S. Hunt , C. B. Brook

Within a cosmological hydrodynamical simulation, we form a disc galaxy with sub- components which can be assigned to a thin stellar disc, thick disk, and a low mass stellar halo via a chemical decomposition. The thin and thick disc…

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…

星系天体物理 · 物理学 2024-11-11 Boquan Chen , Yuan-Sen Ting , Michael Hayden

In this paper we study the underlying stellar population of a sample of 65 nearby early-type galaxies predominantly located in low density environments. Ages, metallicities and [alpha/Fe] ratios have been derived through the comparison of…

天体物理学 · 物理学 2010-10-28 F. Annibali , A. Bressan , R. Rampazzo , W. W. Zeilinger , L. Danese

The space velocities and Galactic orbital elements of stars calculated from the currently available high-accuracy observations in our summary catalog of spectroscopic magnesium abundances in dwarfs and subgiants in the solar neighborhood…

天体物理学 · 物理学 2015-06-24 V. A. Marsakov , T. V. Borkova

The Milky Way's progenitor experienced several merger events which left their imprints on the stellar halo, including the Gaia-Sausage/Enceladus. Recently, it has been proposed that this event perturbed the proto-disk and gave rise to a…

星系天体物理 · 物理学 2020-03-10 João A. S. Amarante , Leandro Beraldo e Silva , Victor P. Debattista , Martin C. Smith

The variation of metal production over time and its dilution in the interstellar medium depend on the star formation and gas accretion rates. Measuring age-chemistry relations across the Milky Way disk provides key constraints on the gas…

星系天体物理 · 物理学 2025-05-28 Valeria Cerqui , Misha Haywood , Owain Snaith , Paola Di Matteo , Laia Casamiquela

(Abridged) Recent spectroscopic surveys have begun to explore the Galactic disk system outside the solar neighborhood on the basis of large data samples. In this way, they provide valuable information for testing spatial and temporal…

In this letter we examine the evolution of the radial metallicity gradient induced by secular processes, in the disk of an $N$-body Milky Way-like galaxy. We assign a [Fe/H] value to each particle of the simulation according to an initial,…

星系天体物理 · 物理学 2015-06-18 A. Curir , A. L. Serra , A. Spagna , M. G. Lattanzi , P. Re Fiorentin , A. Diaferio

The detailed age-chemical abundance relations of stars measures time-dependent chemical evolution.These trends offer strong empirical constraints on nucleosynthetic processes, as well as the homogeneityof star-forming gas. Characterizing…

星系天体物理 · 物理学 2022-03-23 Yuxi , Lu , Melissa Ness , Tobias Buck , Joel Zinn

[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 present a comprehensive study of the kinematic properties of the different Galactic disk populations, as defined by the chemical abundance ratios and stellar ages, across a large disk volume (4.5 $\leq$ R $\leq$ 15.0 kpc and $|Z|$ $\leq$…

星系天体物理 · 物理学 2024-03-05 Weixiang Sun , Yang Huang , Han Shen , Chun Wang , Huawei Zhang , Zhijia Tian , Xiaowei Liu , Biwei Jiang

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…

We present an analysis of very metal-poor (VMP) and metal-poor stars ($-3.0 < \mathrm{Fe/H]} < -1.5$) in the Gaia BP/RP or XP catalog, which reveals two distinct metallicity distribution functions (MDFs) in regions of the Galactic disk…

星系天体物理 · 物理学 2026-03-24 Boquan Chen , Matthew Orkney , Yuan-Sen Ting , Michael Hayden

We investigate the chemical properties of local galaxies within a cosmological framework in the hierarchical picture of galaxy formation. To this aim, we use a hierarchical semi-analytic model which includes the contribution from (i) low…

宇宙学与河外天体物理 · 物理学 2015-05-13 Francesco Calura , Nicola Menci

We employ N-body, smoothed particle hydrodynamical simulations, including detailed treatment of chemical enrichment, to follow a gas-rich merger which results in a galaxy with disk morphology. We trace the kinematic, structural and chemical…

天体物理学 · 物理学 2009-01-19 Chris Brook , Simon Richard , Daisuke Kawata , Hugo Martel , Brad K. Gibson

The entire evolution of the Milky Way, including its mass-assembly and star-formation history, is imprinted onto the chemo-dynamical distribution function of its member stars, f(x, v, [X/H]), in the multi-dimensional phase space spanned by…

星系天体物理 · 物理学 2015-06-18 Kohei Hattori , Yuzuru Yoshii , Timothy C. Beers , Daniela Carollo , Young Sun Lee

From exploratory studies and theoretical expectations it is known that simplifying approximations in spectroscopic analysis (LTE, 1D) lead to systematic biases of stellar parameters and abundances. These biases depend strongly on surface…

太阳与恒星天体物理 · 物理学 2017-10-04 Maria Bergemann , Remo Collet , Ralph Schoenrich , Rene Andrae , Mikhail Kovalev , Gregory Ruchti , Camilla J. Hansen , Zazralt Magic

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…

天体物理学 · 物理学 2009-11-07 A. Ibukiyama , N. Arimoto

The velocity dispersions of stars near the Sun are known to increase with stellar age, but age can be difficult to determine so a proxy like the abundance of alpha elements (e.g., Mg) with respect to iron, [alpha/Fe], is used. Here we…

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