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Context. Globular clusters are considered key objects for understanding the formation and evolution of the Milky Way. In this sense, the characterisation of their chemical and orbital parameters can provide constraints on chemical evolution models of the Galaxy. Aims. We use the heavy element abundances of globular clusters to trace their overall behaviour in the Galaxy, with the aim to analyse potential relations between the hot H-burning and s-process elements. Methods. We measured the content of Cu I and s- and r-process elements (Y II, Ba II, La II, and Eu II) in a sample of 210 giant stars in 18 galactic globular clusters from high-quality UVES spectra. These clusters span a broad metallicity range and the sample is the largest that has been uniformly analysed to date, with respect to heavy elements in globular clusters. Results. The Cu abundances did not show a considerable spread in the sample, nor any correlation with Na, indicating that the Na nucleosynthesis process does not affect the Cu abundance. Most GCs closely follow the Cu, Y, Ba, La, and Eu field stars' distribution, revealing a similar chemical evolution. The Y abundances in mid-metallicity regime GCs (−1.10 dex < [Fe/H] < −1.80 dex) display a mildly significant correlation with the Na abundance, which ought to be further investigated. Finally, we do not find any significant difference between the n-capture abundances among GCs with either Galactic and extragalactic origins. [ABSTRACT FROM AUTHOR]

Globular clusters have been widely studied in terms of light element variations present in their different stellar populations. However, the nature of the polluter(s) responsible for this phenomenon is still debated. The study of heavy elements and their relation to light ones can provide further constraints. In particular, we aim to explore the possible contribution of asymptotic giant branch stars of different stellar masses to the internal pollution in the cluster. We derive abundances of elements from different nucleosynthetic chains, such as Na, Mg, Ca, Sc, Cu, Y, and Ba. We did not find clear relations between the light s-process elements (represented by Y ii) or heavy ones (represented by Ba ii) with light elements (Li, Na, or Al). This indicates that the polluter(s) responsible for the Na (Al) or Li production does not produce large amounts of Y ii and Ba ii. Furthermore, the comparison with models discards a possible significant contribution to the cluster pollution from AGB stars with masses lower than 5 M⊙. In addition, we found a potential CH star in our sample. [ABSTRACT FROM AUTHOR]

This paper presents a chemical abundance analysis of 217 stars in the metal-poor globular cluster NGC 6752, distributed from the turn-off to the lower red giant branch. Al and Li abundances were derived through spectral synthesis applied to spectra collected with FLAMES, in both GIRAFFE and UVES modes. The work aims to gain insight into the nature of the polluter(s) responsible for the abundance variations and the C-N, Na-O, Al-Mg anticorrelations associated with the multiple-population phenomenon. We found a plateau at A (Li) = 2.33 ± 0.06 dex in unevolved stars, with the average Li content decreasing continuously down to ∼1.25 dex at the bottom of the red giant branch. As expected in the classic anticorrelation scenario, we found stars low in Al and high in Li abundance, and stars high in Al and low in Li. However, in addition, we also found evidence of Al-rich, second-generation stars with high Li content. This finding suggests the need for Li production, known to happen in intermediate-mass (∼4–8 M⊙) asymptotic giant branch stars through the Cameron–Fowler mechanism. It is worth noting that the Li abundance observed in Al-rich stars never exceeds that in Al-poor stars. [ABSTRACT FROM AUTHOR]

We present an elemental abundance analysis of high-resolution spectra for five giant stars spatially located within the innermost regions of the bulge globular cluster NGC 6522 and derive Fe, Mg, Al, C, N, O, Si, and Ce abundances based on H-band spectra taken with the multi-object APOGEE-north spectrograph from the SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. Of the five cluster candidates, two previously unremarked stars are confirmed to have second-generation (SG) abundance patterns, with the basic pattern of depletion in C and Mg simultaneous with enrichment in N and Al as seen in other SG globular cluster populations at similar metallicity. In agreement with the most recent optical studies, the NGC 6522 stars analyzed exhibit (when available) only mild overabundances of the s-process element Ce, contradicting the idea that NGC 6522 stars are formed from gas enriched by spinstars and indicating that other stellar sources such as massive AGB stars could be the primary polluters of intra-cluster medium. The peculiar abundance signatures of SG stars have been observed in our data, confirming the presence of multiple generations of stars in NGC 6522. [ABSTRACT FROM AUTHOR]