Results 1 to 10 of about 8,310 (262)

Kinematic-chemical Analysis and Time Tagging for the Diagonal Ridge Structure of the Galactic Outer Disk with LAMOST Red-giant Branch Stars

open access: yesThe Astronomical Journal, 2023
We investigate the kinematic-chemical distribution of red-giant branch stars from the LAMOST survey crossed matched with Gaia DR2 proper motions, and present time tagging for the well-known ridge structures (diagonal distributions for V _R in the R , V ...
Peng Yang   +4 more
doaj   +1 more source

The Metal-weak Milky Way Stellar Disk Hidden in the Gaia–Sausage–Enceladus Debris: The APOGEE DR17 View

open access: yesThe Astrophysical Journal, 2023
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 abundances ...
Sofia Feltzing, Diane Feuillet
doaj   +1 more source

Chemodynamical Analysis of Metal-rich High-eccentricity Stars in the Milky Way's Disk

open access: yesThe Astrophysical Journal, 2023
We present a chemodynamical analysis of 11,562 metal-rich, high-eccentricity halo-like main-sequence stars, which have been referred to as the Splash or Splashed Disk, selected from the Sloan Digital Sky Survey and Large Sky Area Multi-Object Fiber ...
Ayeon Lee   +4 more
doaj   +1 more source

A Blueprint for the Milky Way’s Stellar Populations. IV. A String of Pearls—the Galactic Starburst Sequence

open access: yesThe Astrophysical Journal, 2023
We continue our series of papers on phase-space distributions of stars in the Milky Way based on photometrically derived metallicities and Gaia astrometry, with a focus on the halo−disk interface in the local volume.
Deokkeun An   +3 more
doaj   +1 more source

The Observable Properties of Galaxy Accretion Events in Milky Way–like Galaxies in the FIRE-2 Cosmological Simulations

open access: yesThe Astrophysical Journal, 2023
In the Λ-Cold Dark Matter model of the universe, galaxies form in part through accreting satellite systems. Previous works have built an understanding of the signatures of these processes contained within galactic stellar halos.
Danny Horta   +9 more
doaj   +1 more source

The Tilt of the Velocity Ellipsoid of Different Galactic Disk Populations

open access: yesThe Astrophysical Journal, 2023
The tilt of the velocity ellipsoid is a helpful tracer of the gravitational potential of the Milky Way. In this paper, we use nearly 140,000 red clump (RC) stars selected from LAMOST and Gaia to make a detailed analysis of the tilt of the velocity ...
Weixiang Sun, Han Shen, Xiaowei Liu
doaj   +1 more source

The Rapid Onset of Stellar Bars in the Baryon-dominated Centers of Disk Galaxies

open access: yesThe Astrophysical Journal, 2023
Recent observations of high-redshift galactic disks ( z ≈ 1–3) show a strong negative trend in the dark-matter (DM) fraction f _DM with increasing baryon surface density.
Joss Bland-Hawthorn   +3 more
doaj   +1 more source

The Imprint of Clump Formation at High Redshift. II. The Chemistry of the Bulge

open access: yesThe Astrophysical Journal, 2023
In Paper I, we showed that clumps in high-redshift galaxies, having a high star formation rate density (Σ _SFR ), produce disks with two tracks in the [Fe/H]–[ α /Fe] chemical space, similar to that of the Milky Way’s (MW’s) thin+thick disks.
Victor P. Debattista   +13 more
doaj   +1 more source

The R-Process Alliance: Chemodynamically Tagged Groups. II. An Extended Sample of Halo r-process-enhanced Stars

open access: yesThe Astrophysical Journal, 2023
Orbital characteristics based on Gaia Early Data Release 3 astrometric parameters are analyzed for ∼1700 r -process-enhanced (RPE; [Eu/Fe] > +0.3) metal-poor stars ([Fe/H] ≤ −0.8) compiled from the R -Process Alliance, the GALactic Archaeology with ...
Derek Shank   +10 more
doaj   +1 more source

Distant Echoes of the Milky Way’s Last Major Merger

open access: yesThe Astrophysical Journal, 2023
The majority of the Milky Way’s stellar halo consists of debris from our galaxy’s last major merger, the Gaia-Sausage-Enceladus (GSE). In the past few years, stars from the GSE have been kinematically and chemically studied in the inner 30 kpc of our ...
Vedant Chandra   +11 more
doaj   +1 more source

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