Constraints on the history of Galactic spiral arms revealed by Gaia GSP-Spec alpha-elements

Abstract

The distribution of chemical elements in the Galactic disc can reveal fundamental clues on the physical processes that led to the current configuration of our Galaxy. We map chemical azimuthal variations in the disc using individual stellar chemical abundances and discuss their possible connection with the spiral arms and other perturbing mechanisms. Using Gaia Data Release 3, we examine [Ca/Fe] and [Mg/Fe] fluctuations in a ~4 kpc region around the Sun, focusing on bright giant stars. We implemented a kernel density estimator technique to enhance the chemical inhomogeneities. We observe radial gradients and azimuthal fluctuations in [alpha/Fe] for young (<150 Myr) and old (>2 Gyr) stars, with amplitudes varying according to the studied element. In young stars, those within spiral arms (e.g., Sagittarius-Carina and Local arms) are generally more metal and calcium-rich (~0-0.19 dex) but show lower [Ca/Fe] (~0.06 dex) and [Mg/Fe] (~0.05 dex) compared to inter-arm regions, suggesting enhanced iron production in spiral arms. These [alpha/Fe] depletions are analysed in light of theoretical scenarios and compared to a 2D chemical evolution model with multiple spiral patterns. For the old sample, [Ca/Fe] maps reveal deficiencies along a segment of the Local arm identified by young stars. We caution that, for this old sample, the quality of the obtained maps might be limited along a specific line-of-sight, due to the Gaia scanning law. This study transitions our understanding of disc chemical evolution from a 1D radial view to a more detailed 2D framework incorporating radial, azimuthal, and small-scale variations. Individual chemical abundances prove essential for tracing spiral arms in disc galaxies. We recommend models and simulations incorporate alpha-abundance trends to better address spiral arm lifetimes.

References in corpus (39)

• Gaia Data Release 3: Summary of the content and survey properties
• Trigonometric Parallaxes Of High-Mass Star Forming Regions: Our View Of The Milky Way
• Dawes Review 4: Spiral Structures in Disc Galaxies
• Gaia Data Release 3: Analysis of RVS spectra using the General Stellar Parametriser from spectroscopy
• Gaia Data Release 3: Astrophysical parameters inference system (Apsis) I -- methods and content overview
• On the fine structure of the Cepheid metallicity gradient in the Galactic thin disk
• Updated Gaia-2MASS 3D maps of Galactic interstellar dust
• The Abundance Properties of Nearby Late-Type Galaxies.I. The Data
• Gaia Data Release 3: Mapping the asymmetric disc of the Milky Way
• Transient spirals as superposed instabilities
• Galactic spiral structure revealed by Gaia EDR3
• Three-dimensional extinction maps: Inverting inter-calibrated extinction catalogues
• Quantifying the impact of the Large Magellanic Cloud on the structure of the Milky Way's dark matter halo using Basis Function Expansions
• The origin of large peculiar motions of star-forming regions and spiral structures of our Galaxy
• On the Milky Way spiral arms from open clusters in Gaia EDR3
• The spiral pattern rotation speed of the Galaxy and the corotation radius with GAIA DR2
• The Star Formation Rate of the Milky Way as seen by Herschel
• Metallicity Structure in the Milky Way Disk Revealed by Galactic HII Regions
• Large Metallicity Variations in the Galactic Interstellar Medium
• Hic sunt dracones: Cartography of the Milky Way spiral arms and bar resonances with Gaia Data Release 2
• The phase spiral in Gaia DR3
• 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
• The Galactic habitable zone around M and FGK stars with chemical evolution models with dust
• Bar effect on gas-phase abundance gradients. I. Data sample and chemical abundances
• Migration and Mixing in the Galactic Disc from Encounters between Sagittarius and the Milky Way
• Oxygen, sulfur, and iron radial abundance gradients of classical Cepheids across the Galactic thin disk
• Long-Lived Spiral Structure for Galaxies with Intermediate Size Bulges
• FEDReD II : 3D Extinction Map with 2MASS and Gaia DR2 data
• Spiral-like features in the disc revealed by Gaia DR3 radial actions
• Using classical Cepheids to study the far side of the Milky Way disk. II. The spiral structure in the first and fourth Galactic quadrants
• 2D-Galactic chemical evolution: the role of the spiral density wave
• The AMBRE Project: Solar neighbourhood chemodynamical constraints on Galactic disc evolution
• The cerium content of the Milky Way as revealed by Gaia DR3 GSP-Spec abundances
• ISM metallicity variations across spiral arms in disk galaxies: the impact of local enrichment and gas migration in the presence of radial metallicity gradient
• 2D chemical evolution models II. Effects of multiple spiral arm patterns on O, Eu, Fe and Ba abundance gradients
• The Non-Axisymmetric Influence: Radius and Angle-Dependent Trends in a Barred Galaxy
• FEDReD III : Unraveling the 3D structure of Vela
• First spiral arm detection using dynamical mass measurements of the Milky Way disk

Cited by in corpus (6)

• The Gaia spectroscopic catalogue of exoplanets and host stars
• Bar-spiral interaction produces radial migration and star formation bursts
• Metal-rich stellar counterpart of the Radcliffe Wave and the 3D chemical footprints of the Milky Way spiral arms
• The Galactic inner spiral arms revealed by the Gaia ESO Survey chemical abundances. Metallicity and [Mg/Fe] ratios
• Signatures of simulated spiral arms on radial actions
• Mapping the Milky Way with Gaia Bp/Rp spectra-IV: the broken and asymmetric density profile of the stellar disk traced by a large sample of red clumps