González-Díaz, DaniloFernández-Trincado, José G.Villanova, SandroGeisler, DougBarbuy, BeatrizMinniti, DanteBeers, Timothy C.Bidin, Christian MoniMauro, FrancescoMuñoz, CesarTang, BaitianSoto, MarioMonachesi, AntonelaLane, Richard R.Frelijj, Heinz2023-12-052023-12-052023-12-01Monthly Notices of the Royal Astronomical Society, Volume 526, Issue 4, Pages 6274 - 6283, 1 December 202300358711https://repositorio.unab.cl/xmlui/handle/ria/54412INDEXACIÓN: SCOPUS.This study presents the results concerning six red giant stars members of the globular cluster NGC 6558. Our analysis utilized high-resolution near-infrared spectra obtained through the CAPOS initiative (the APOgee Survey of Clusters in the Galactic Bulge), which focuses on surveying clusters within the Galactic Bulge, as a component of the Apache Point Observatory Galactic Evolution Experiment II survey (APOGEE-2). We employ the Brussels Automatic Code for Characterizing High accUracy Spectra (BACCHUS) code to provide line-by-line elemental-abundances for Fe-peak (Fe, Ni), α-(O, Mg, Si, Ca, Ti), light-(C, N), odd-Z (Al), and the s-process element (Ce) for the four stars with high-signal-to-noise ratios. This is the first reliable measure of the CNO abundances for NGC 6558. Our analysis yields a mean metallicity for NGC 6558 of 〈[Fe/H]〉 = −1.15 ± 0.08, with no evidence for a metallicity spread. We find a Solar Ni abundance, 〈[Ni/Fe]〉 ∼ +0.01, and a moderate enhancement of α-elements, ranging between +0.16 and [removed] +0.99, along with a low level of carbon, [C/Fe] < −0.12. This behaviour of Nitrogen-Carbon is a typical chemical signature for the presence of multiple stellar populations in virtually all GCs; this is the first time that it is reported in NGC 6558. We also observed a remarkable consistency in the behaviour of all the chemical species compared to the other CAPOS bulge GCs of the same metallicity. © The Author(s) 2023.engalaxy: globular clusters: individual: NGC 6558stars: abundancesstars: chemically peculiarTechniques: spectroscopicArtículoCC BY 4.0 DEED Attribution 4.0 International10.1093/mnras/stad3178