Type Ia supernova feedback effects on globular clusters of different masses

¹ INAF – OAS, Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, via Gobetti 93/3, 40129 Bologna, Italy
² Dipartimento di Fisica e Astronomia “Augusto Righi”, Alma Mater Studiorum - Unversità di Bologna, via Gobetti 93/3, 40129 Bologna, Italy
³ Dipartimento di Fisica e Astronomia “Galileo Galilei”, Univerisità di Padova, Vicolo dell’Osservatorio 3, 35122 Padova, Italy
⁴ Institut für Theoretische Astrophysik, ZAH, Universität Heidelberg, Albert-Ueberle-Straße 2, 69120 Heidelberg, Germany
⁵ INFN – Padova, Via Marzolo 8, 35131 Padova, Italy
⁶ Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell’Insubria, via Valleggio 11, 22100 Como, Italy
⁷ INFN, Sezione di Milano-Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
⁸ Institute for Research in Fundamental Sciences (IPM), Larak Garden, 19395-5531 Tehran, Iran
⁹ Univ Lyon, Univ Lyon1, Ens de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, 69230 Saint-Genis-Laval, France

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Received: 1 April 2025
Accepted: 25 September 2025

Abstract

Through 3D hydrodynamical simulations, we explore the impact of Type Ia supernova (SN) explosions on the star formation history and chemical properties of second-generation (SG) stars in young globular clusters with masses of 10⁵−10⁶M_⊙. We assume that the SG is formed out of the asymptotic giant branch (AGB) ejecta of first-generation stars plus pristine interstellar medium gas which is modelled as a uniform gas moving at a constant velocity towards the cluster. We tested two values for the infalling gas density of 10⁻²⁴ and 10⁻²³ g cm⁻³. Type Ia SNe start to explode together with the release of gas from the most massive AGB stars. Three simulated models are analysed. In the low-mass and low-density scenario, we find SNe Ia quench star formation that however restarts when the gas cools down again in between two explosions. The SG stars are dominated by a He-rich population (Y > 0.33), which is poorly diluted by pristine gas. In the high-mass models, star formation is mildly affected, while the He composition is significantly altered as exploding SNe prevent the accretion of pristine gas, and therefore extremely helium-rich stars form. In the high-density model, such weak gas accretion leads to a maximum enhancement in the helium mass fraction that is much larger than the observed one and that does not correlate with the initial cluster mass as is found in models without Type Ia SNe. As for the iron content, small spreads have been found in all models, but the SG is less homogeneous than the FG, at variance with current observations.