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J/A+A/600/A104   Potassium abundance in 3 globular clusters (Mucciarelli+, 2017)

The potassium abundance in the globular clusters NGC104, NGC6752 and NGC6809. Mucciarelli A., Merle T., Bellazzini M. <Astron. Astrophys. 600, A104 (2017)> =2017A&A...600A.104M (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Stars, population II ; Abundances Keywords: techniques: spectroscopic - globular clusters: individual: NGC104 - globular clusters: individual: NGC6752 - globular clusters: individual: NGC6809 - stars: abundances Abstract: We derived Potassium abundances in red giant branch stars in the Galactic globular clusters NGC 104 (144 stars), NGC 6752 (134 stars) and NGC 6809 (151 stars) using high-resolution spectra collected with FLAMES at the ESO - Very Large Telescope. In the considered samples we do not find significant intrinsic spreads in [K/Fe] (confirming the previous findings by Carretta et al.), at variance with the cases of the massive clusters NGC 2419 and NGC 2808. Additionally, marginally significant [K/Fe]-[O/Fe] anti-correlations are found in NGC 104 and NGC 6809, and [K/Fe]-[Na/Fe] correlations are found in NGC 104 and NGC 6752. No evidence of [K/Fe]-[Mg/Fe] anti-correlation are found. The results of our analysis are consistent with a scenario in which the process leading to the multi-populations in globular clusters implies also enrichment in the K abundance, the amplitude of the associated [K/Fe] enhancement becoming measurable only in stars showing the most extreme effects of O and Mg depletion. Stars enhanced in [K/Fe] have been found so far only in clusters harbouring some Mg-poor stars, while the other globulars, without a Mg-poor sub-population, show small or null [K/Fe] spreads. Description: Potassium-over-iron abundance ratios for red giant branch stars in three globular clusters obtained using FLAMES spectra: 144 stars in NGC104, 134 stars in NGC6752, 151 stars in NGC6809. Atmospheric parameters (effective temperature, surface gravities and micorturbulent velocities) are provided. All the abundances include NLTE corrections. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 48 429 Atmospheric parameters and [K/Fe] abundance ratios
See also: J/A+A/464/927 : NGC 6752 red giants abundances (Carretta+, 2007) J/A+A/505/117 : 15 globular clusters red giants abundances (Carretta+, 2009) J/A+A/505/139 : 17 globular clusters red giants abundances (Carretta+, 2009) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 7 A7 --- Cluster Cluster name 9- 15 I7 --- ID Star ID (1) 17- 20 I4 K Teff Effective temperature 22- 25 F4.2 [cm/s2] log(g) Surface gravity 27- 30 F4.2 km/s vt Microturbulent velocity 32- 37 F6.2 mA EW Equivalent width of the K line at 7699 Å 39- 43 F5.2 [Sun] [K/Fe] Relative abundance [K/Fe] 45- 48 F4.2 [Sun] e_[K/Fe] Uncertainty on [K/Fe]
Note (1): from Carretta et al., 2007, Cat. J/A+A/464/927 (Cl* NGC 6752 CBG NNNNN), 2009a, Cat. J/A+A/505/117 ([CBG2009] NGC NNNN NNNNNNN) and 2009b, Cat. J/A+A/505/139 ([CBG2009] NGC NNNN NNNNNNN).
Acknowledgements: Alessio Mucciarelli, alessio.mucciarelli2(at)unibo.it
(End) Patricia Vannier [CDS] 14-Feb-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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