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Journal Articles The Astrophysical Journal Year : 2022

Fluorine Abundances in the Galactic Nuclear Star Cluster

Solange Ramírez
  • Function : Author
Katia Cunha
Verne Smith
Nikos Prantzos
Kris Sellgren
Simone Daflon


Abstract Abundances of fluorine ( 19 F), as well as isotopic ratios of 16 O/ 17 O, are derived in a sample of luminous young (∼10 7 –10 8 yr) red giants in the Galactic center (with galactocentric distances ranging from 0.6–30 pc), using high-resolution infrared spectra and vibration-rotation lines of H 19 F near λ 2.3 μ m. Five of the six red giants are members of the Nuclear star cluster that orbits the central supermassive black hole. Previous investigations of the chemical evolution of 19 F in Galactic thin and thick-disk stars have revealed that the nucleosynthetic origins of 19 F may be rather complex, resulting from two, or more, astrophysical sites; fluorine abundances behave as a primary element with respect to Fe abundances for thick-disk stars and as a secondary element in thin-disk stars. The Galactic center red giants analyzed fall within the thin-disk relation of F with Fe, having near-solar, to slightly larger, abundances of Fe (〈[Fe/H]〉 = +0.08 ± 0.04), with a slight enhancement of the F/Fe abundance ratio (〈[F/Fe]〉 = +0.28 ± 0.17). In terms of their F and Fe abundances, the Galactic center stars follow the thin-disk population, which requires an efficient source of 19 F that could be the winds from core-He burning Wolf–Rayet stars, or thermally pulsing AGB stars, or a combination of both. The observed increase of [F/Fe] with increasing [Fe/H] found in thin-disk and Galactic center stars is not predicted by any published chemical evolution models that are discussed, thus a quantitative understanding of yields from the various possible sources of 19 F remains unknown.

Dates and versions

hal-03876365 , version 1 (28-11-2022)



Rafael Guerço, Solange Ramírez, Katia Cunha, Verne Smith, Nikos Prantzos, et al.. Fluorine Abundances in the Galactic Nuclear Star Cluster. The Astrophysical Journal, 2022, 929 (1), pp.24. ⟨10.3847/1538-4357/ac5c55⟩. ⟨hal-03876365⟩


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