Elemental Abundances in Giants in NGC 3201, a Globular Cluster with a Retrograde Orbit

1998 ◽  
Vol 116 (2) ◽  
pp. 765-781 ◽  
Author(s):  
Guillermo Gonzalez ◽  
George Wallerstein
Keyword(s):  
Globular Cluster ◽  
Elemental Abundances ◽  
Retrograde Orbit

Elemental Abundances in Five Stars in M54, A Globular Cluster Associated with the Sagittarius Galaxy

1999 ◽  
Vol 118 (3) ◽  
pp. 1245-1251 ◽  
Author(s):  
Jeffery A. Brown ◽  
George Wallerstein ◽  
Guillermo Gonzalez
Keyword(s):  
Globular Cluster ◽  
Elemental Abundances

Elemental Abundances of Three Red Giants in Terzan 7, a Globular Cluster Associated with the Sagittarius Galaxy

2004 ◽  
Vol 127 (1) ◽  
pp. 373-379 ◽  
Author(s):  
Graina Tautvaiien ◽  
George Wallerstein ◽  
Doug Geisler ◽  
Guillermo Gonzalez ◽  
Corinne Charbonnel
Keyword(s):  
Globular Cluster ◽  
Red Giants ◽  
Elemental Abundances

scholarly journals Nucleosynthesis in the Stellar Systems ω Centauri and M22

2011 ◽  
Vol 28 (1) ◽  
pp. 28-37 ◽  
Author(s):  
G. S. Da Costa ◽  
A. F. Marino
Keyword(s):  
Globular Cluster ◽  
Total Mass ◽  
Large Range ◽  
Stellar System ◽  
Stellar Systems ◽  
Elemental Abundances ◽  
Two Systems ◽  
Red Giant ◽  
Using Data ◽  
Giant Branch Stars

AbstractThe stellar system ω Centauri (ω Cen) is well known for the large range in elemental abundances among its member stars. Recent work has indicated that the globular cluster M22 (NGC 6656) also possesses an internal abundance range, albeit substantially smallerthan that in ω Cen. Here we compare, as a function of [Fe/H], element-to-iron ratios in the two systems for a number of different elements using data from abundance analyses of red giant branch stars. It appears that the nucleosynthetic enrichment processes were very similar in these two systems despite the substantial difference in total mass.

scholarly journals Gaia-ESO Survey: Detailed elemental abundances in red giants of the peculiar globular cluster NGC1851

2021 ◽  
Author(s):  
G. Tautvaisiene ◽  
A. Drazdauskas ◽  
A. Bragaglia ◽  
S. L. Martell ◽  
E. Pancino ◽  
...  
Keyword(s):  
Globular Cluster ◽  
Red Giants ◽  
Elemental Abundances

scholarly journals The enigmatic globular cluster UKS 1 obscured by the bulge: H-band discovery of nitrogen-enhanced stars

2020 ◽  
Vol 643 ◽  
pp. A145 ◽  
Author(s):  
José G. Fernández-Trincado ◽  
Dante Minniti ◽  
Timothy C. Beers ◽  
Sandro Villanova ◽  
Doug Geisler ◽  
...  
Keyword(s):  
Spectroscopic Study ◽  
Globular Cluster ◽  
Strong Evidence ◽  
Proper Motion ◽  
Spectroscopic Data ◽  
Globular Clusters ◽  
Elemental Abundances ◽  
The Mean ◽  
Lower Carbon ◽  
Good Agreement

The presence of nitrogen-enriched stars in globular clusters provides key evidence for multiple stellar populations (MPs), as has been demonstrated with globular cluster spectroscopic data towards the bulge, disk, and halo. In this work, we employ the VVV Infrared Astrometric Catalogue (VIRAC) and the DR16 SDSS-IV release of the APOGEE survey to provide the first detailed spectroscopic study of the bulge globular cluster UKS 1. Based on these data, a sample of six selected cluster members was studied. We find the mean metallicity of UKS 1 to be [Fe/H] = −0.98 ± 0.11, considerably more metal-poor than previously reported, and a negligible metallicity scatter, typical of that observed by APOGEE in other Galactic globular clusters. In addition, we find a mean radial velocity of 66.1 ± 12.9 km s−1, which is in good agreement with literature values, within 1σ. By selecting stars in the VIRAC catalogue towards UKS 1, we also measure a mean proper motion of (μαcos(δ), μδ) = (−2.77 ± 0.23, −2.43 ± 0.16) mas yr−1. We find strong evidence for the presence of MPs in UKS 1, since four out of the six giants analysed in this work have strong enrichment in nitrogen ([N/Fe] ≳ +0.95) accompanied by lower carbon abundances ([C/Fe] ≲ −0.2). Overall, the light- (C, N), α- (O, Mg, Si, Ca, Ti), Fe-peak (Fe, Ni), Odd-Z (Al, K), and the s-process (Ce, Nd, Yb) elemental abundances of our member candidates are consistent with those observed in globular clusters at similar metallicity. Furthermore, the overall star-to-star abundance scatter of elements exhibiting the multiple-population phenomenon in UKS 1 is typical of that found in other global clusters (GCs), and larger than the typical errors of some [X/Fe] abundances. Results from statistical isochrone fits in the VVV colour-magnitude diagrams indicate an age of 13.10−1.29+0.93 Gyr, suggesting that UKS 1 is a fossil relic in the Galactic bulge.

scholarly journals Elemental Abundances of Three Giants in Terzan 7

2002 ◽  
Vol 207 ◽  
pp. 171-173
Author(s):  
George Wallerstein ◽  
Guillermo Gonzalez ◽  
Doug Geisler
Keyword(s):  
Globular Cluster ◽  
Resolving Power ◽  
The Sun ◽  
Elemental Abundances

Using VLT UVES spectra of resolving power near 23,000 we have analyzed three stars in Terzan 7, a globular cluster associated with the Sagittarius Galaxy. We find [Fe/H] = −0.61±0.1, [O/Fe] = +0.25, [α/Fe] = +0.23 dex, and an enhancement of r/s elements as compared with the Sun and Arcturus.

Recent Advances in High Dispersion Spectroscopy of Globular Cluster Stars

1988 ◽  
Vol 132 ◽  
pp. 525-530
Author(s):  
Raffaele G. Gratton
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
High Dispersion ◽  
Photographic Material ◽  
Recent Advances ◽  
Metal Abundances ◽  
Ccd Detectors ◽  
Major Progress

The use CCD detectors has allowed a major progress in abundance derivations for globular cluster stars in the last years. Abundances deduced from high dispersion spectra now correlates well with other abundance indicators. I discuss some problems concerning the derivation of accurate metal abundances for globular clusters using high dispersion spectra from both the old photographic and the most recent CCD data. The discrepant low abundances found by Cohen (1980), from photographic material for M71 giants, are found to be due to the use of too high microturbulences.

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