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相关论文: Exploring the Galaxy's halo and very metal-weak th…

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The low-metallicity, kinematically interesting dwarf stars studied by Stephens \& Boesgaard (2002, SB02) are re-examined using Gaia DR2 astrometry, and updated model atmospheres and atomic line data. New stellar parameters are determined…

星系天体物理 · 物理学 2020-10-23 Stephanie Monty , Kim A. Venn , James M. M. Lane , Deborah Lokhorst , David Yong

We characterize the Gaia-Enceladus-Sausage kinematic structure recently discovered in the Galactic halo using photometric metallicities from the SkyMapper survey, and kinematics from Gaia radial velocities measurements. By examining the…

星系天体物理 · 物理学 2020-07-08 Diane K Feuillet , Sofia Feltzing , Christian Sahlholdt , Luca Casagrande

(Abbreviated) We present a detailed analysis of the space motions of 1203 solar-neighborhood stars with metal abundances [Fe/H] <= -0.6, on the basis of a recently revised and supplemented catalog of metal-poor stars selected without…

天体物理学 · 物理学 2009-05-29 M. Chiba , T. C. Beers

We present a catalogue of 551,214 main-sequence stars in the local ($d < 2$ kpc) Galactic thick disk and halo, based on a search of stars with large proper motions ($\mu_{\mathrm{tot}} > 40.0$ mas/yr) in the Gaia Early Data Release 3. We…

星系天体物理 · 物理学 2022-01-05 Bokyoung Kim , Sebastien Lépine

Metal-poor stars are key for studying the formation and evolution of the Galaxy. Evidence of the early mergers that built up the Galaxy remains in the distributions of abundances, kinematics, and orbital parameters of its stars. Several…

星系天体物理 · 物理学 2023-09-06 André Rodrigo da Silva , Rodolfo Smiljanic

Extremely metal-poor stars are intrinsically rare, but emerging methods exist to accurately classify them from all-sky Gaia XP low-resolution spectra. To assess their overall accuracy for targeting metal-poor stars, we present a…

太阳与恒星天体物理 · 物理学 2026-01-30 Riley Thai , Andrew R. Casey , Alexander Ji , Vedant Chandra , Hans-Walter Rix

We explore the chemo-dynamical properties of a sample of very metal-poor (VMP) stars selected from the Hamburg/ESO survey, matched with Gaia EDR3, in the phase-space identified by the three integrals of motion ($L_z$, $E$, $I_3$). Disk and…

星系天体物理 · 物理学 2023-04-12 Daniela Carollo , Norbert Christlieb , Patricia B. Tissera , Emanuel Sillero

Studies of the early chemical evolution of some larger dwarf galaxies ( $>10^7$ solar masses) are limited by the small number of stars known at low metallicities in these systems. Here we present metallicities and carbon abundances for…

星系天体物理 · 物理学 2020-10-14 Anirudh Chiti , Kylie Y. Hansen , Anna Frebel

The fastest moving stars provide insight into several fundamental properties of the Galaxy, including the escape velocity as a function of Galactocentric radius, the total mass, and the nature and frequency of stellar encounters with the…

太阳与恒星天体物理 · 物理学 2018-09-05 Keith Hawkins , Rosemary F. G. Wyse

We improve the identification and isolation of individual stellar populations in the Galactic halo based on an updated set of empirically calibrated stellar isochrones in the Sloan Digital Sky Survey (SDSS) and Pan-STARRS 1 (PS1)…

星系天体物理 · 物理学 2021-02-10 Deokkeun An , Timothy C. Beers

An abundance analysis is presented of 60 metal-poor stars drawn from catalogues of nearby stars provided by Ariyanto et al. (2005) and Schuster et al. (2006). In an attempt to isolate a sample of metal-weak thick disc stars, we applied the…

天体物理学 · 物理学 2009-11-13 Bacham E. Reddy , David L. Lambert

Previous studies based on the analysis of Gaia DR2 data have revealed that accreted stars, possibly originating from a single progenitor satellite, are a significant component of the halo of our Galaxy, potentially constituting most of the…

星系天体物理 · 物理学 2019-11-27 P. Di Matteo , M. Haywood , M. D. Lehnert , D. Katz , S. Khoperskov , O. N. Snaith , A. Gómez , N. Robichon

We attempt to determine the relative fraction of stars that have undergone significant radial migration by studying the orbital properties of metal-rich ([Fe/H]$>0.1$) stars within 2 kpc of the Sun using a sample of more than 3,000 stars…

We have for the first time identified the early stellar disk in the Milky Way by using a combination of elemental abundances and kinematics. Using data from APOGEE DR17 and Gaia we select stars in the Mg-Mn-Al-Fe plane with elemental…

星系天体物理 · 物理学 2023-06-28 Sofia Feltzing , Diane Feuillet

We explore the metal-poor regime of the Galactic disk on the distribution of stars in the [$\alpha$/M]-$V_{\phi}$ plane, to identify the most metal-poor thin disk (MPTnD) stars belonging to the low-$\alpha$ sequence. Chemical abundances and…

星系天体物理 · 物理学 2024-12-10 Guozhen Hu , Zhengyi Shao , Erbil Gugercinoglu , Wenyuan Cui

The emergence of the disc in our Galaxy and the relation of the thick and thin disc formation and evolution is still a matter of debate. The chemo-dynamical characterization of disc stars is key to resolve this question, in particular at…

We present evidence that multiple accretion events are required to explain the origin of the $Gaia$-Sausage and Enceladus (GSE) structures, based on an analysis of dynamical properties of main-sequence stars from the Sloan Digital Sky…

星系天体物理 · 物理学 2021-04-28 Young Kwang Kim , Young Sun Lee , Timothy C. Beers , Jae-Rim Koo

Large spectroscopic surveys plus Gaia astrometry have shown us that the inner stellar halo of the Galaxy is dominated by the debris of Gaia Enceladus/Sausage (GES). With the richness of data at hand, there are a myriad of ways these…

星系天体物理 · 物理学 2023-06-02 Andreia Carrillo , Alis J. Deason , Azadeh Fattahi , Thomas M. Callingham , Robert J. J. Grand

R-process enhanced metal-poor stars (\EuFe$\geq+0.3$ and \FeH$\leq-1.0$) are rare objects whose study can provide clues to the astrophysical sites of the rapid neutron capture process. In this study, we investigate the detailed chemical…

太阳与恒星天体物理 · 物理学 2025-04-16 A. R. da Silva , R. Smiljanic
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