APOGEE-2S Mg-Al anti-correlation of the metal-poor globular cluster NGC 2298

Baeza, Ian; Fernandez-Trincado, Jose G.; Villanova, Sandro; Geisler, Doug; Minniti, Dante; Garro, Elisa R.; Barbuy, Beatriz; Beers, Timothy C.; Lane, Richard R.

Abstract

We present detailed elemental abundances and radial velocities of stars in the metal-poor globular cluster (GC) NGC 2298, based on near-infrared high-resolution (R similar to 22 500) spectra of 12 members obtained during the second phase of the Apache Point Observatory Galactic Evolution Experiment (APOGEE-2) at Las Campanas Observatory as part of the seventeenth Data Release (DR 17) of the Sloan Digital Sky Survey IV (SDSS-IV). We employed the Brussels Automatic Code for Characterizing High accuracy Spectra (BACCHUS) software to investigate abundances for a variety of species including alpha elements (Mg, Si, and Ca), the odd-Z element Al, and iron-peak elements (Fe and Ni) located in the innermost regions of NGC 2298. We find a mean and median metallicity [Fe/H] = -1.76 and -1.75, respectively, with a star-to-star spread of 0.14 dex, which is compatible with the internal measurement errors. Thus, we find no evidence for an intrinsic [Fe/H] abundance spread in NGC 2298. The typical alpha-element enrichment in NGC 2298 is overabundant relative to the Sun, and it follows the trend of other metal-poor GCs. We confirm the existence of an Al-enhanced population in this cluster, which is clearly anti-correlated with Mg, indicating the prevalence of the multiple-population phenomenon in NGC 2298.

Más información

Título según WOS: APOGEE-2S Mg-Al anti-correlation of the metal-poor globular cluster NGC 2298
Título de la Revista: ASTRONOMY & ASTROPHYSICS
Volumen: 662
Editorial: EDP SCIENCES S A
Fecha de publicación: 2022
DOI:

10.1051/0004-6361/202243475

Notas: ISI