The Gaia-ESO survey: Open clusters as tracers of galactic chemical evolution

¹ School of Physical and Chemical Sciences, University of Canterbury, Kirkwood Ave, Canterbury, New Zealand
² Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
³ Institute of Theoretical Physics and Astronomy, Faculty of Physics, Vilnius University, Sauletekio av. 3, 10257 Vilnius, Lithuania
⁴ INAF – Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5, 50125 Firenze, Italy
⁵ INAF – Osservatorio di Astrofisica e Scienza dello Spazio, via P. Gobetti 93/3, 40129 Bologna, Italy
⁶ Lund Observatory, Division of Astrophysics, Department of Physics, Lund University, Box 118, 22100 Lund, Sweden
⁷ Centro de Astrobiología, CSIC-INTA, Camino bajo del castillo s/n, 28692, Villanueva de la Canãda, Madrid, Spain
⁸ School of Physics, University of New South Wales, Sydney, NSW, Australia
⁹ INAF – Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, 90134 Palermo, Italy

^★ Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 14 July 2025
Accepted: 14 October 2025

Abstract

Aims. We investigate the formation and evolutionary trajectory of the Milky Way’s inner and outer galactic regions using stars from open clusters in the Gaia-ESO OC survey.

Methods. Using numerical simulations from Chempy, we leveraged Markov chain Monte Carlo sampling techniques to derive galactic evolutionary parameters for each open cluster by fitting measured abundances of elements C, N, O, Mg, Si, Ca, Ti, Fe, Mn, Zn, Y, and Ba.

Results. We find differing evolutionary histories between the inner and outer regions of the Milky Way that align with variations in the slope of the initial mass function, the rate of Type Ia supernovae, and the galactic metallicity gradient traced by open clusters.

Conclusions. Our results support established galactic formation and evolutionary theories, highlighting that the inner Galaxy had a short and intense early star formation epoch followed by reduced activity. In contrast, the outer Galaxy maintained a more sustained star formation history.