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A Blueprint for the Milky Way’s Stellar Populations. IV. A String of Pearls—the Galactic Starburst Sequence
- Title
- A Blueprint for the Milky Way’s Stellar Populations. IV. A String of Pearls—the Galactic Starburst Sequence
- Authors
- An D.; Beers T.C.; Lee Y.S.; Masseron T.
- Ewha Authors
- 안덕근
- SCOPUS Author ID
- 안덕근
- Issue Date
- 2023
- Journal Title
- Astrophysical Journal
- ISSN
- 0004-637X
- Citation
- Astrophysical Journal vol. 952, no. 1
- Publisher
- Institute of Physics
- Indexed
- SCIE; SCOPUS
- Document Type
- Article
- Abstract
- 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. To exploit various photometric databases, we develop a method of empirically calibrating synthetic stellar spectra based on a comparison with observations of stellar sequences and individual stars in the Sloan Digital Sky Survey, the SkyMapper Sky Survey, and the Pan-STARRS1 surveys, overcoming band-specific corrections employed in our previous work. In addition, photometric zero-point corrections are derived to provide an internally consistent photometric system with a spatially uniform metallicity zero-point. Using our phase-space diagrams, we find a remarkably narrow sequence in the rotational velocity (v ϕ) versus metallicity ([Fe/H]) space for a sample of high proper-motion stars (>25 mas yr−1), which runs along Gaia Sausage/Enceladus (GSE) and the Splash substructures and is linked to the disk, spanning nearly 2 dex in [Fe/H]. Notably, a rapid increase of v ϕ from a nearly zero net rotation to ∼180 km s−1 in a narrow metallicity interval (−0.6 ≲ [Fe/H] ≲ −0.4) suggests that some of these stars emerged quickly on a short gas-depletion timescale. Through measurements of a scale height and length, we argue that these stars are distinct from those heated dynamically by mergers. This chain of high proper-motion stars provides additional support for recent discoveries suggesting that a starburst took place when the young Milky Way encountered the gas-rich GSE progenitor, which eventually led to the settling of metal-enriched gas onto the disk. © 2023. The Author(s). Published by the American Astronomical Society.
- DOI
- 10.3847/1538-4357/acd5cb
- Appears in Collections:
- 사범대학 > 과학교육과 > Journal papers
- Files in This Item:
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An_2023_ApJ_952_66.pdf(15.23 MB)
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