Potassium: a new actor on the globular cluster chemical evolution stage. The case of NGC 2808
arXiv:1501.03161 · doi:10.1088/0004-637X/801/1/68
Abstract
We derive [K/Fe] abundance ratios for 119 stars in the globular cluster NGC 2808, all of them having O, Na, Mg and Al abundances homogeneously measured in previous works. We detect an intrinsic star-to-star spread in the Potassium abundance. Moreover [K/Fe] abundance ratios display statistically significant correlations with [Na/Fe] and [Al/Fe], and anti-correlations with [O/Fe] and [Mg/Fe]. All the four Mg deficient stars ([Mg/Fe]<0.0) discovered so far in NGC 2808 are enriched in K by ~0.3 dex with respect to those with normal [Mg/Fe]. NGC 2808 is the second globular cluster, after NGC 2419, where a clear Mg-K anti-correlation is detected, albeit of weaker amplitude. The simultaneous correlation/anti-correlation of [K/Fe] with all the light elements usually involved in the chemical anomalies observed in globular cluster stars, strongly support the idea that these abundance patterns are due to the same self-enrichment mechanism that produces Na-O and Mg-Al anti-correlations. This finding suggests that detectable spreads in K abundances may be typical in the massive globular clusters where the self-enrichment processes are observed to produce their most extreme manifestations.
arXiv commentAccepted for publication by ApJ, 5 pages, 3 figures
References in corpus (27)
- A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
- Multiple populations in globular clusters. Lessons learned from the Milky Way globular clusters
- Fast rotating massive stars and the origin of the abundance patterns in galactic globular clusters
- Formation and Dynamical Evolution of Multiple Stellar Generations in Globular Clusters
- Na-O Anticorrelation and HB. VIII. Proton-capture elements and metallicities in 17 globular clusters from UVES spectra
- Massive binaries as the source of abundance anomalies in globular clusters
- Modeling the Metallicity Distribution of Globular Clusters
- A helium spread among the main sequence stars in NGC 2808
- Early Disc Accretion as the Origin of Abundance Anomalies in Globular Clusters
- DAOSPEC: an automatic code for measuring equivalent widths in high-resolution stellar spectra
- Detailed abundances of a large sample of giant stars in M 54 and in the Sagittarius nucleus
- Na-O Anticorrelation And HB I. The Na-O anticorrelation in NGC 2808
- News from the Galactic suburbia: the chemical composition of the remote globular cluster NGC 2419
- Multi-Element Abundance Measurements from Medium-Resolution Spectra. I. The Sculptor Dwarf Spheroidal Galaxy
- Looking outside the Galaxy: the discovery of chemical anomalies in 3 old Large Magellanic Cloud clusters
- The Bizarre Chemical Inventory of NGC 2419, An Extreme Outer Halo Globular Cluster
- The peculiar Horizontal Branch of NGC 2808
- GALA: an automatic tool for the abundance analysis of stellar spectra
- Hubble Space Telescope Observations of an Outer Field in Omega Centauri: A Definitive Helium Abundance
- Another Non-segregated Blue Straggler Population in a Globular Cluster: the Case of NGC 2419
- Super AGB and AGB evolution and the chemical inventory in NGC 2419
- NGC 2419: a large and extreme second generation in a currently undisturbed cluster
- Multiple populations in Omega Centauri: a cluster analysis of spectroscopic data
- Three discrete groups with homogeneous chemistry along the red giant branch in the globular cluster NGC 2808
- Potassium in globular cluster stars: comparing normal clusters to the peculiar cluster NGC 2419
- Star-to-star Na and O abundance variations along the red giant branch in NGC 2808
- Evidence for multiple populations in the massive globular cluster NGC 2419 from deep uVI LBT photometry
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- What is a globular cluster? An observational perspective
- A unique model for the variety of multiple populations formation(s) in globular clusters: a temporal sequence
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- Homogeneous Analysis of Globular Clusters from the APOGEE Survey with the BACCHUS Code. II. The Southern Clusters and Overview
- Five groups of red giants with distinct chemical composition in the globular cluster NGC 2808
- Triangulum II: Not Especially Dense After All
- A homogeneous analysis of globular clusters from the APOGEE survey with the BACCHUS code. I. The Northern clusters
- Revisiting nucleosynthesis in globular clusters: the case of NGC 2808 and the role of He and K
- The Relationship Between Globular Cluster Mass, Metallicity, and Light Element Abundance Variations
- Detailed Chemical Abundances in NGC 5824: Another Metal-Poor Globular Cluster with Internal Heavy Element Abundance Variations
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- A Chemical Composition Survey of the Iron-Complex Globular Cluster NGC 6273 (M 19)
- Multiple stellar populations and their evolution in globular clusters: A nucleosynthesis perspective
- On Potassium and Other Abundance Anomalies of Red Giants in NGC 2419
- Detailed Abundances of 15 Stars in the Metal-Poor Globular Cluster NGC 4833
- The Potassium abundance in the globular clusters NGC104, NGC6752 and NGC6809
- Chemical Complexity in the Eu-enhanced Monometallic Globular Cluster NGC 5986
- Survey of multiple populations in globular clusters among very low-mass stars
- A broad perspective on multiple abundance populations in the globular cluster NGC 1851
- A stellar census in globular clusters with MUSE: Multiple populations chemistry in NGC 2808
- Abundances of Na, Mg, and K in the atmospheres of red giant branch stars of Galactic globular cluster 47 Tucanae
- Catalog of Chromium, Cobalt, and Nickel Abundances in Globular Clusters and Dwarf Galaxies
- Star clusters forming in a low metallicity starburst -- rapid self-enrichment by (very) massive stars
- Excess of Ca (and Sc) produced in globular cluster multiple populations: a first census in 77 Galactic globular clusters
- r-process Abundance Patterns in the Globular Cluster M92
- Light Element Discontinuities Suggest an Early Termination of Star Formation in the Globular Cluster NGC 6402 (M14)
- APOGEE-2S Discovery of Light- and Heavy-Element Abundance Correlations in the Bulge Globular Cluster NGC 6380
- The Mg-K anti-correlation in Omega Centauri
- Chemistry of multiple stellar populations in the mono-metallic, in situ, bulge globular cluster NGC 6388
- Searching for multiple populations in star clusters using the China Space Station Telescope
- Search for Extremely Metal-Poor Stars with GEMINI-N/GRACES I. Chemical-Abundance Analysis
- HST observations of the globular cluster NGC 6402 (M14) and its peculiar multiple populations
- Strömgren uvby photometry of the peculiar globular cluster NGC 2419
- Hubble Space Telescope photometry of multiple stellar populations in the inner parts of NGC 2419
- On the discovery of K-enhanced and possibly Mg-depleted stars throughout the Milky Way
- Potassium abundances in multiple stellar populations of the globular cluster NGC 4833
- NGC 6388 reloaded: some like it hot, but not too much
- New sub-grouping of multiple stellar populations in NGC 2808 based on low-resolution spectroscopy
- Abundance of zinc in the red giants of Galactic globular cluster 47 Tucanae
- Abundances of Mg and K in the atmospheres of turn-off stars in Galactic globular cluster 47 Tucanae
- Curiouser and curiouser: the peculiar chemical composition of the Li/Na-rich star in Omega Centauri
- Homogenous abundances of Mg, Si, Ca, and Ti for about 1500 red giants in 16 globular clusters from FLAMES spectra
- Calcium Excess in Novae: Beyond Nuclear Physics Uncertainties
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