Effects of Multiple Spiral Arm Patterns on the Abundance Gradients of Heavy Elements

Understanding how spiral structures influence the chemical evolution of the Galactic disc remains a key issue in Galactic archaeology. Recent advances in two-dimensional chemical evolution modeling allow us to account for the impact of multiple spiral arm patterns, each characterized by different pattern speeds, on the redistribution of elements throughout the Galaxy. In this work, we explore the influence of multi-pattern spiral arms on the radial abundance gradients of heavy elements in the Galactic disc. We focus on a scenario in which, during the most recent stage of evolution, corotation spans the entire disc. Our results indicate that the observed dispersion in the abundance gradients of O, Fe, Eu, and Ba, as traced by Cepheids, can be successfully reproduced if all galactocentric radii have effectively acted as corotation regions over the past 1–3 Gyr. We also note that such an extended phase has previously been identified as necessary to explain the azimuthal abundance variations reported in Gaia DR3 and Gaia-ESO survey data along local and inner spiral arms.