Chemical abundance analysis of red giant branch stars in the globular cluster E3

Abstract

Context. Globular clusters are known to host multiple stellar populations, which are a signature of their formation process. The globular cluster E3 is one of the few low-mass globulars that is thought not to host multiple populations. Aims. We investigate red giant branch stars in E3 with the aim of providing a first detailed chemical inventory for this cluster, we determine its radial velocity, and we provide additional insights into the possible presence of multiple populations in this cluster. Methods. We obtained high-resolution FLAMES-UVES/VLT spectra of four red giant branch stars likely members of E3. We performed a local thermodynamic equilibrium abundance analysis based on one-dimensional plane parallel ATLAS9 model atmospheres. Abundances were derived from line equivalent widths or spectrum synthesis. Results. We measured abundances of Na and of iron peak (Fe, V, Cr, Ni, Mn), $\alpha$ (Mg, Si, Ca, Ti), and neutron capture elements (Y, Ba, Eu). The mean cluster heliocentric radial velocity, metallicity, and sodium abundance ratio are v${}_{helio}$=12.6$\pm$0.4 km/s ($\sigma$=0.6$\pm$0.2 km/s), [Fe/H]=-0.89$\pm$0.08 dex, and [Na/Fe]=0.18$\pm$0.07 dex, respectively. The low Na abundance with no appreciable spread is suggestive of a cluster dominated by first-generation stars in agreement with results based on lower resolution spectroscopy. The low number of stars observed does not allow us to rule out a minor population of second-generation stars. The observed chemical abundances are compatible with the trends observed in Milky Way stars.

arXiv comment9 pages, 7 figures, 3 tables, accepted for publication in A&A

References in corpus (48)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Gaia Data Release 2. Summary of the contents and survey properties
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• The Gaia mission
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• Elemental Abundance Survey of The Galactic Thick Disk
• Na-O Anticorrelation and HB. VII. The chemical composition of first and second-generation stars in 15 globular clusters from GIRAFFE spectra
• Stellar Chemical Signatures And Hierarchical Galaxy Formation
• The Chemical Compositions of Galactic Disk F and G Dwarfs
• Fast rotating massive stars and the origin of the abundance patterns in galactic globular clusters
• Multiple Stellar Populations in Globular Clusters
• Na-O Anticorrelation and HB. VIII. Proton-capture elements and metallicities in 17 globular clusters from UVES spectra
• The O-Na and Mg-Al Anticorrelations in Turn-Off and early Subgiants in Globular Clusters
• The ACS Survey of Galactic Globular Clusters. I. Overview and Clusters Without Previous HST Photometry
• Properties of stellar generations in Globular Clusters and relations with global parameters
• The ACS Survey of Galactic Globular Clusters. VII. Relative Ages
• The ACS Survey of Galactic Globular Clusters. XII. Photometric Binaries along the Main-Sequence
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. IX. The Atlas of Multiple Stellar Populations
• A library of high resolution synthetic stellar spectra from 300nm to 1.8 micron with solar and alpha-enhanced composition
• Spectroscopic and Photometric evidence of two stellar populations in the Galactic Globular Cluster NGC6121 (M4)
• Abundances for metal-poor stars with accurate parallaxes I. Basic data
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. V. Constraints on Formation Scenarios
• The exotic chemical composition of the Sagittarius dwarf Spheroidal galaxy
• Pal 12 As A Part of the Sgr Stream; the Evidence From Abundance Ratios
• The Gaia-ESO Survey. Mg-Al anti-correlation in iDR4 globular clusters
• The chemical composition of red giant stars in four intermediate-age clusters of the Large Magellanic Cloud
• Ruprecht 106: the first single population Globular Cluster?
• A Search for Stars of Very Low Metal Abundance. V. Photoelectric UBV Photometry of Metal-Weak Candidates from the Northern HK Survey
• Age as a Major Factor in the Onset of Multiple Populations in Stellar Clusters
• Measuring helium abundance difference in giants of NGC 2808
• Searching for multiple stellar populations in the massive, old open cluster Berkeley 39
• Multiple populations in the old and massive Small Magellanic Cloud globular cluster NGC121
• Low-resolution spectroscopy of main sequence stars belonging to 12 Galactic globular clusters. I. CH and CN band strength variations
• Terzan 8: a Sagittarius-flavoured globular cluster
• First evidence of fully spatially mixed first and second generations in globular clusters: the case of NGC 6362
• The Search for Multiple Populations in Magellanic Cloud Clusters III: No evidence for Multiple Populations in the SMC cluster NGC 419
• No evidence of chemical anomalies in the bimodal turnoff cluster NGC 1806 in the LMC
• Accretion of pristine gas and dilution during the formation of multiple-population globular clusters
• NGC 6535: the lowest mass Milky Way globular cluster with a Na-O anti-correlation? Cluster mass and age in the multiple population context
• Formation of the Galactic Halo
• Aluminium abundances in five discrete stellar populations of the globular cluster NGC 2808
• Chemical abundances of giant stars in NGC 5053 and NGC 5634, two globular clusters associated with the Sagittarius dwarf Spheroidal galaxy?
• A spectroscopic study of the Globular Cluster NGC 4147
• NGC6362: the least massive globular cluster with chemically distinct multiple populations
• No evidence for multiple stellar populations in the low-mass Galactic globular cluster E 3
• ESO452-SC11: The lowest mass globular cluster with a potential chemical inhomogeneity
• The chemical composition of NGC5824, a globular cluster without iron spread but with an extreme Mg-Al anticorrelation
• Ghosts of Milky Way's past: the globular cluster ESO 37-1 (E 3)

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• Discovery of a hot post-AGB star in Galactic globular cluster E3