TY - JOUR
T1 - Chemical abundances in the metal-intermediate GC NGC 6723
AU - Crestani, Juliana
AU - Alves-Brito, Alan
AU - Bono, Giuseppe
AU - Puls, Arthur A.
AU - Alonso-García, Javier
N1 - Publisher Copyright:
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2019/6/25
Y1 - 2019/6/25
N2 - We have performed a detailed spectral analysis of the inner halo Galactic globular cluster (GC) NGC 6723 using high-resolution (R ≈ 22 000-48 000) spectra for for 11 red giant branch stars collected with MIKE (Magellan) and FEROS (MPG/ESO). This globular is located at the minimum of the bimodal metallicity distribution of GCs, which suggests that it might be an excellent transitional system between metal-intermediate and metal-rich GCs. In spite of its metal-intermediate status, it is characterized by an extended horizontal branch and by a large number of RR Lyrae stars. We investigated abundances of a variety of species, including light, α-, Fe-peak, and neutron-capture elements. We found a mean metallicity [Fe/H]=-0.93 ± 0.05 dex and typical α-enrichment ([α Fe] ≈ 0.39) that follows the trend of metal-poor and metal-intermediate GCs. The same outcome applies for light metals (Na, Al), Fe-peak (V, Cr, Mn, Fe, Co, Ni, Cu) and s/r-process elements (Ba, Eu), and for the classical anticorrelation: Na-O and Mg-Al. The current findings further support the evidence that the chemical enrichment of NGC 6723 is more in line with metal-intermediate GCs and their lower metallicity counterparts, and it does not bring forward the prodrome of the metal-rich regime.
AB - We have performed a detailed spectral analysis of the inner halo Galactic globular cluster (GC) NGC 6723 using high-resolution (R ≈ 22 000-48 000) spectra for for 11 red giant branch stars collected with MIKE (Magellan) and FEROS (MPG/ESO). This globular is located at the minimum of the bimodal metallicity distribution of GCs, which suggests that it might be an excellent transitional system between metal-intermediate and metal-rich GCs. In spite of its metal-intermediate status, it is characterized by an extended horizontal branch and by a large number of RR Lyrae stars. We investigated abundances of a variety of species, including light, α-, Fe-peak, and neutron-capture elements. We found a mean metallicity [Fe/H]=-0.93 ± 0.05 dex and typical α-enrichment ([α Fe] ≈ 0.39) that follows the trend of metal-poor and metal-intermediate GCs. The same outcome applies for light metals (Na, Al), Fe-peak (V, Cr, Mn, Fe, Co, Ni, Cu) and s/r-process elements (Ba, Eu), and for the classical anticorrelation: Na-O and Mg-Al. The current findings further support the evidence that the chemical enrichment of NGC 6723 is more in line with metal-intermediate GCs and their lower metallicity counterparts, and it does not bring forward the prodrome of the metal-rich regime.
KW - Galaxy: abundances
KW - globular clusters: individual: NGC 6723
KW - stars: abundances
UR - http://www.scopus.com/inward/record.url?scp=85070099129&partnerID=8YFLogxK
U2 - 10.1093/mnras/stz1674
DO - 10.1093/mnras/stz1674
M3 - Article
SN - 0035-8711
VL - 487
SP - 5463
EP - 5474
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -