APOGEE-2S view of the globular cluster Patchick 125 (Gran 3) New metallicity and elemental abundances from high-resolution spectroscopy

Fernandez-Trincado, Jose G.; Minniti, Dante; Garro, Elisa R.; Villanova, Sandro

Abstract

We present detailed elemental abundances, radial velocity, and orbital elements for Patchick 125, a recently discovered metal-poor globular cluster (GC) in the direction of the Galactic bulge. Near-infrared high-resolution (Rx2004;similar to 22x2006;500) spectra of two members were obtained during the second phase of the Apache Point Observatory Galactic Evolution Experiment at Las Campanas Observatory as part of the sixteenth Data Release (DR 16) of the Sloan Digital Sky Survey. We investigated elemental abundances for four chemical species, including alpha- (Mg, Si), Fe-peak (Fe), and odd-Z (Al) elements. We find a metallicity covering the range from [Fe/H] = -1.69 to -1.72, suggesting that Patchick 125 likely exhibits a mean metallicity ⟨[Fe/H]⟩similar to-1.7, which represents a significant increase in metallicity for this cluster compared to previous low-resolution spectroscopic analyses. We also found a mean radial velocity of 95.9 km s(-1), which is similar to 21.6 km s(-1) higher than reported in the literature. The observed stars exhibit an alpha-enrichment ([Mg/Fe] less than or similar to 0.20, and [Si/Fe] less than or similar to +0.30) that follows the typical trend of metal-poor GCs. The aluminum abundance ratios for the present two member stars are enhanced in [Al/Fe] greater than or similar to +0.58, which is a typical enrichment characteristic of the so-called 'second-generation' of stars in GCs at similar metallicity. This supports the possible presence of the multiple-population phenomenon in Patchick 125, as well as its genuine GC nature. Further, Patchick 125 shows a low-energy, low-eccentric (< 0.4) and retrograde orbit captured by the inner Galaxy, near the edge of the bulge. We confirm that Patchick 125 is a genuine metal-poor GC, which is currently trapped in the vicinity of the Milky Way bulge.

Más información

Título según WOS: APOGEE-2S view of the globular cluster Patchick 125 (Gran 3) New metallicity and elemental abundances from high-resolution spectroscopy
Título de la Revista: ASTRONOMY & ASTROPHYSICS
Volumen: 657
Editorial: EDP SCIENCES S A
Fecha de publicación: 2022
DOI:

10.1051/0004-6361/202142222

Notas: ISI