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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…

Context. The [Mg/Fe] abundance ratios are a fundamental fossil signature to trace the chemical evolution of the disc. Despite of the huge observational and theoretical effort, discrepancies between models and data are still present and…

星系天体物理 · 物理学 2022-07-20 Marco Palla , Pablo Santos-Peral , Alejandra Recio-Blanco , Francesca Matteucci

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

A few topics concerning the early chemical evolution of the Milky Way are critically discussed. In particular, it is argued that: 1) Observed abundance patterns of extremely metal poor stars (of Pop. II) do not constrain the mass range of…

天体物理学 · 物理学 2007-05-23 Nikos Prantzos

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…

天体物理学 · 物理学 2009-11-10 Chris B. Brook , Brad K. Gibson , Hugo Martel , Daisuke Kawata

Large-scale surveys will provide spectroscopy for $\sim$50 million resolved stars in the Milky Way and Local Group. However, these data will have a high degree of heterogeneity and most will be low-resolution ($R<10000$), posing challenges…

太阳与恒星天体物理 · 物理学 2023-07-19 Nathan R. Sandford , Daniel R. Weisz , Yuan-Sen Ting

We compute the evolution of different abundance ratios in the Milky Way (MW) for two different sets of stellar yields. In one of them stellar rotation is taken into account and we investigate its effects on the chemical evolution model…

天体物理学 · 物理学 2009-11-10 Cristina Chiappini , Francesca Matteucci , Georges Meynet

We use 297 042 main sequence turn-off stars selected from the LSS-GAC to determine the radial and vertical gradients of stellar metallicity of the Galactic disk in the anti-center direction. We determine ages of those turn-off stars by…

We investigate the chemical evolution of the Milky Way disc exploring various schemes of recent (last several Gyr) star formation episodes, as reported in recent observational works. We use a semi-analytical model with parametrized radial…

星系天体物理 · 物理学 2025-02-12 Tianxiang Chen , Nikos Prantzos

Spectroscopic surveys of the Galaxy reveal that its disc stars exhibit a spread in $\mathrm{[\alpha/Fe]}$ at fixed $\mathrm{[Fe/H]}$, manifest at some locations as a bimodality. The origin of these diverse, and possibly distinct, stellar…

星系天体物理 · 物理学 2018-05-02 J. Ted Mackereth , Robert A. Crain , Ricardo P. Schiavon , Joop Schaye , Tom Theuns , Matthieu Schaller

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…

The ``2-process Model'' is a promising technique for interpreting stellar chemical abundance data from large-scale surveys (e.g., SDSS-IV/V, GALAH), enabling more quantitative empirical studies of differences in chemical enrichment history…

Understanding the Milky Way disc formation requires characterising its structural and kinematic properties as functions of stellar age. Using red giant stars from APOGEE DR17 and Gaia DR3, we model the age-dependent stellar kinematics with…

We derive the star formation histories of eight dwarf spheroidal (dSph) Milky Way satellite galaxies from their alpha element abundance patterns. Nearly 3000 stars from our previously published catalog (Paper II) comprise our data set. The…

We provide a detailed map of the ages and metallicities of turnoff stars in the Milky Way disc based on data from GALAH DR3 and Gaia EDR3. From this map, we identify previously undetected features in the age-metallicity distribution of disc…

星系天体物理 · 物理学 2022-01-05 Christian L. Sahlholdt , Sofia Feltzing , Diane K. Feuillet

We employ our Bayesian Machine Learning framework BINGO (Bayesian INference for Galactic archaeOlogy) to obtain high-quality stellar age estimates for 68,360 red giant and red clump stars present in the 17th data release of the Sloan…

The formation and chemical evolution of the Milky Way Galaxy is numerically simulated by developing a Monte Carlo approach to predict the elemental abundance gradients and other galactic features using the revised solar abundance. The…

星系天体物理 · 物理学 2018-10-10 Sandeep Sahijpal , Tejpreet Kaur

The signatures of the formation and evolution of a galaxy are imprinted in its stars. Their velocities, ages, and chemical compositions present major constraints on models of galaxy formation, and on various processes such as the gas…

We present a low metallicity map of the Milky Way consisting of $\sim$111,000 giants with $-3.5 \lesssim$ [Fe/H] $\lesssim -$0.75, based on public photometry from the second data release of the SkyMapper survey. These stars extend out to…

星系天体物理 · 物理学 2021-04-28 Anirudh Chiti , Mohammad K. Mardini , Anna Frebel , Tatsuya Daniel

Using a semi-analytical model of the evolution of the Milky Way, we show how secular evolution can create distinct overdensities in the phase space of various properties (e.g. age vs metallicity or abundance ratios vs age) corresponding to…