Evidence of AGB pollution in Galactic globular clusters from the Mg-Al anticorrelations observed by the APOGEE survey

Abstract

We study the formation of multiple populations in globular clusters (GC), under the hypothesis that stars in the second generation formed from the winds of intermediate-mass stars, ejected during the asymptotic giant branch (AGB) phase, possibly diluted with pristine gas, sharing the same chemical composition of first-generation stars. To this aim, we use the recent APOGEE data, which provide the surface chemistry of a large sample of giant stars, belonging to clusters that span a wide metallicity range. The APOGEE data set is particularly suitable to discriminate among the various pollution scenarios proposed so far, as it provides the surface abundances of Mg and Al, the two elements involved in a nuclear channel extremely sensitive to the temperature, hence to the metallicity of the polluters. The present analysis shows a remarkable agreement between the observations and the theoretical yields from massive AGB stars. In particular, the observed extension of the depletion of Mg and O and the increase in Al is well reproduced by the models and the trend with the metallicity is also fully accounted for. This study further supports the idea that AGB stars were the key players in the pollution of the intra-cluster medium, from which additional generations of stars formed in GC.

Accepted on ApJ letters

References in corpus (4)

• Fast rotating massive stars and the origin of the abundance patterns in galactic globular clusters
• Formation and Dynamical Evolution of Multiple Stellar Generations in Globular Clusters
• Origin of multiple stellar populations in globular clusters and their helium enrichment
• Exploring Anticorrelations and Light Element Variations in Northern Globular Clusters Observed by the APOGEE Survey

Cited by in corpus (23)

• A homogeneous analysis of globular clusters from the APOGEE survey with the BACCHUS code. I. The Northern clusters
• Atypical Mg-poor Milky Way field stars with globular cluster second-generation like chemical patterns
• Revisiting nucleosynthesis in globular clusters: the case of NGC 2808 and the role of He and K
• The Relationship Between Globular Cluster Mass, Metallicity, and Light Element Abundance Variations
• CAPOS: The bulge Cluster APOgee Survey I. Overview and initial ASPCAP results
• Homogeneous Analysis of Globular Clusters from the APOGEE Survey with the BACCHUS Code $-$ III. $\omega$ Cen
• The enigmatic globular cluster UKS~1 obscured by the bulge: \textit{H}-band discovery of nitrogen-enhanced stars
• The origin of discrete multiple stellar populations in globular clusters
• Chemical Complexity in the Eu-enhanced Monometallic Globular Cluster NGC 5986
• APOGEE discovery of a chemically atypical star disrupted from NGC 6723 and captured by the Milky Way bulge
• Jurassic: A Chemically Anomalous Structure in the Galactic Halo
• Discovery of a large population of Nitrogen-Enhanced stars in the Magellanic Clouds
• MgAl burning chain in Omega Centauri
• CAPOS: The bulge Cluster APOgee Survey III. Spectroscopic Tomography of Tonantzintla 2
• APOGEE-2S Discovery of Light- and Heavy-Element Abundance Correlations in the Bulge Globular Cluster NGC 6380
• Formation of globular clusters with internal abundance spreads in r-process elements: strong evidence for prolonged star formation
• Nucleosynthetic yields of Z=$10^{-5}$ intermediate-mass stars
• High Resolution Spectroscopic Abundances of Red Giant Branch Stars in NGC 6681
• Characterization of M-stars in the LMC in the JWST era
• APOGEE Detection of N-rich stars in the tidal tails of Palomar 5
• Chemical analysis of the Bulge Globular Cluster NGC 6553
• CAPOS: The bulge Cluster APOgee Survey V. Elemental abundances of the bulge globular cluster HP 1
• On the star formation efficiencies and evolution of multiple stellar generations in Globular Clusters