Spatial metallicity variations of mono-temperature stellar populations revealed by early-type stars in LAMOST
arXiv:2304.02958 · doi:10.1051/0004-6361/202245761
Abstract
We investigate the radial metallicity gradients and azimuthal metallicity distributions on the Galactocentric -- plane using mono-temperature stellar populations selected from LAMOST MRS young stellar sample. The estimated radial metallicity gradient ranges from 0.015\,dex/kpc to 0.07\,dex/kpc, which decreases as effective temperature decreases (or stellar age increases) at \,K (1.5 Gyr). The azimuthal metallicity excess (metallicity after subtracting radial metallicity gradient, \,[M/H]) distributions exhibit inhomogeneities with dispersions of 0.04\,dex to 0.07\,dex, which decrease as effective temperature decreases. We also identify five potential metal-poor substructures with large metallicity excess dispersions. The metallicity excess distributions of these five metal-poor substructures suggest that they contain a larger fraction of metal-poor stars compared to other control samples. These metal-poor substructures may be associated with high-velocity clouds that infall into the Galactic disk from the Galactic halo, which are not quickly well-mixed with the pre-existing ISM of the Galactic disk. As a result, these high-velocity clouds produce some metal-poor stars and the observed metal-poor substructures. The variations of metallicity inhomogeneities with different stellar populations indicate that high-velocity clouds are not well mixed with the pre-existing Galactic disk ISM within 0.3\,Gyr.
arXiv comment14 pages, 12 figures, Accepted for publication in A&A
References in corpus (41)
- PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
- Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
- Trigonometric Parallaxes of High Mass Star Forming Regions: the Structure and Kinematics of the Milky Way
- New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey
- Trigonometric Parallaxes Of High-Mass Star Forming Regions: Our View Of The Milky Way
- A New Mechanism for Radial Migration in Galactic Disks: Spiral-Bar Resonance Overlap
- Rotational velocities of A-type stars IV. Evolution of rotational velocities
- On the Galactic Disk Metallicity Distribution from Open Clusters I. New Catalogues and Abundance Gradient
- Galactic Metallicity Gradients Derived from a Sample of OB Stars
- HII Region Metallicity Distribution in the Milky Way Disk
- The evolution of the Galactic metallicity gradient from high-resolution spectroscopy of open clusters
- Evolution of the Milky Way with radial motions of stars and gas I. The solar neighborhood and the thin and thick disk
- Chemical Cartography with APOGEE: Large-scale Mean Metallicity Maps of the Milky Way
- Using Cepheids to determine the galactic abundance gradient I. The solar neighbourhood
- Mapping metallicity variations across nearby galaxy disks
- Measuring Radial Orbit Migration in the Milky Way Disk
- Metallicity Gradients in the Milky Way Disk as Observed by the SEGUE Survey
- Abundances of Galactic Anticenter Planetary Nebulae and the Oxygen Abundance Gradient in the Galactic Disk
- On the metallicity gradient of the Galactic disk
- Keeping it Cool: Much Orbit Migration, yet Little Heating, in the Galactic Disk
- Stellar labels for hot stars from low-resolution spectra - I. the HotPayne method and results for 330,000 stars from LAMOST DR6
- The Chemical Evolution Carousel of Spiral Galaxies: Azimuthal Variations of Oxygen Abundance in NGC1365
- Metallicity Fluctuation Statistics in the Interstellar Medium and Young Stars. I. Variance and Correlation
- Chemical abundance patterns in the inner Galaxy: the Scutum Red Supergiant Clusters
- Chemical gradients in the Milky Way from the RAVE data. I. Dwarf stars
- Measuring the mixing scale of the ISM within nearby spiral galaxies
- Chemical gradients in the Milky Way from the RAVE data. II. Giant stars
- Chemical abundances of planetary nebulae towards the direction of the galactic anticenter
- Large Metallicity Variations in the Galactic Interstellar Medium
- Mapping Luminous Hot Stars in the Galaxy
- Azimuthal variations of gas-phase oxygen abundance in NGC 2997
- LAMOST meets Gaia: The Galactic Open Clusters
- Quantifying radial migration in the Milky Way: Inefficient over short timescales but essential to the very outer disc beyond ~15 kpc
- Chemical Cartography with LAMOST and Gaia Reveal Azimuthal and Spiral Structure in the Galactic Disk
- The chemical signature of the Galactic spiral arms revealed by Gaia DR3
- Stellar metallicity variations across spiral arms in disk galaxies with multiple populations
- Revealing the physical properties of gas accreting to haloes in the EAGLE simulations
- Metallicity distributions of mono-age stellar populations of the Galactic disc from the LAMOST Galactic spectroscopic surveys
- Metallicity Distribution of Disk Stars and the Formation History of the Milky Way
- Exploring the stellar rotation of early-type stars in the LAMOST Medium-Resolution Survey. I. Catalog
- A Test for Radial Mixing Using Local Star Samples