Purveyors of fine halos III. Chemical abundance analysis of a potential omega Cen associate

Abstract

Globular clusters (GCs) are important donors to the build-up of the Milky Way (MW) stellar halo, having contributed at the ten percent level over the Galactic history. Stars that originated from the second generation of dissolved or dissolving clusters can be readily identified via distinct light-element signatures such as enhanced N and Na and simultaneously depleted C and O abundances. In this paper we present an extensive chemical abundance analysis of the halo star J110842, which was previously kinematically associated with the massive MW GC $\omega$ Centauri ($\omega$Cen), and we discuss viable scenarios from escape to encounter. Based on a high-resolution, high signal-to-noise spectrum of this star using the UVES spectrograph, we were able to measure 33 species of 31 elements across all nucleosynthetic channels. The star's low metallicity of [FeII/H]=$-2.10$$\pm$0.02(stat.)$\pm 0.07$(sys.) dex places it in the lower sixth percentile of $\omega$Cen's metallicity distribution. We find that all of the heavier-element abundances, from $\alpha$- and Fe-peak elements to neutron-capture elements are closely compatible with $\omega$Cen's broad abundance distribution. However, given the major overlap of this object's abundances with the bulk of all of the MW components, this does not allow for a clear-cut distinction of the star's origin. In contrast, our measurements of an enhancement in CN and its position on the Na-strong locus of the Na-O anticorrelation render it conceivable that it originally formed as a second-generation GC star, lending support to a former association of this halo star with the massive GC $\omega$Cen.

arXiv comment9 pages, 6 figures, accepted for publication in Astronomy & Astrophysics

References in corpus (102)

• The chemical composition of the Sun
• Gaia Data Release 2. Summary of the contents and survey properties
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Gaia Data Release 2: The astrometric solution
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE)
• Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
• The Fourth US Naval Observatory CCD Astrograph Catalog (UCAC4)
• Exploring the Milky Way stellar disk. A detailed elemental abundance study of 714 F and G dwarf stars in the Solar neighbourhood
• Tracing Galaxy Formation with Stellar Halos I: Methods
• The Radial Velocity Experiment (RAVE): first data release
• Galactic chemical evolution: Carbon through Zinc
• The GALAH Survey: Scientific Motivation
• Multiple Stellar Populations in Globular Clusters
• Na-O Anticorrelation and HB. VIII. Proton-capture elements and metallicities in 17 globular clusters from UVES spectra
• Neutron-Capture Elements in the Early Galaxy: Insights from a Large Sample of Metal-Poor Giants
• The Radial Velocity Experiment (RAVE): Fifth Data Release
• Evidence for Two Early Accretion Events That Built the Milky Way Stellar Halo
• A Search for Stars of Very Low Metal Abundance. VI. Detailed Abundances of 313 Metal-Poor Stars
• Detection of massive tidal tails around the globular cluster Pal 5 with SDSS commissioning data
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. IX. The Atlas of Multiple Stellar Populations
• Origin of the system of globular clusters in the Milky Way
• Non-LTE calculations for neutral Na in late-type stars using improved atomic data
• The RAdial Velocity Experiment (RAVE): Fourth data release
• The Rise of the s-Process in the Galaxy
• Evidence from the H3 Survey that the Stellar Halo is Entirely Comprised of Substructure
• The formation and assembly history of the Milky Way revealed by its globular cluster population
• Multiple Stellar Populations in the Globular Cluster omega Centauri as Tracers of a Merger Event
• Formation of omega Centauri from an ancient nucleated dwarf galaxy in the young Galactic disc
• Chemical Abundances for 855 Giants in the Globular Cluster Omega Centauri (NGC 5139)
• The Dual Origin of Stellar Halos
• An Analysis of the Shapes of Interstellar Extinction Curves. VII. Milky Way Spectrophotometric Optical-through-Ultraviolet Extinction and Its R-Dependence
• What is a globular cluster? An observational perspective
• Assessing the Milky Way Satellites Associated with the Sagittarius Dwarf Spheroidal Galaxy
• Evidence from APOGEE for the presence of a major building block of the halo buried in the inner Galaxy
• New Rare Earth Element Abundance Distributions for the Sun and Five r-Process-Rich Very Metal-Poor Stars
• Galactic accretion and the outer structure of galaxies in the CDM model
• Building Late-Type Spiral Galaxies by In-Situ and Ex-Situ Star Formation
• Reverse engineering the Milky Way
• Building the Galactic halo from globular clusters: evidence from chemically unusual red giants
• Sodium-oxygen anticorrelation and neutron capture elements in Omega Centauri stellar populations
• Pal 12 As A Part of the Sgr Stream; the Evidence From Abundance Ratios
• Improved Laboratory Transition Probabilities for Ce II, Application to the Cerium Abundances of the Sun and Five r-process Rich, Metal-Poor Stars, and Rare Earth Lab Data
• Abundances of Cu and Zn in metal-poor stars: clues for Galaxy evolution
• Observational constraints on the origin of the elements. I. 3D NLTE formation of Mn lines in late-type stars
• The Abundance Spread Among Giants and Subgiants in the Globular Cluster Omega Centauri
• The Unique History of the Globular Cluster Omega Centauri
• The origin and evolution of the odd-Z iron-peak elements Sc, V, Mn, and Co in the Milky Way stellar disk
• Chemical Abundances and Kinematics in Globular Clusters and Local Group Dwarf Galaxies and Their Implications for Formation Theories of the Galactic Halo
• Light-element Abundance Variations in the Milky Way Halo
• On the origin of high-velocity runaway stars
• Oxygen abundances in low- and high-alpha field halo stars and the discovery of two field stars born in globular clusters
• Improved Laboratory Transition Probabilities for Er II and Applications to the Erbium Abundances of the Sun and Five r-Process Rich, Metal-Poor Stars
• Search for Extratidal Features Around 17 Globular Clusters in the Sloan Digital Sky Survey
• The metallicity spread and the age-metallicity relation of Omega Centauri
• Atypical Mg-poor Milky Way field stars with globular cluster second-generation like chemical patterns
• Comparing CN and CH Line Strengths in a Homogeneous Spectroscopic Sample of 8 Galactic Globular Clusters
• The Outer Envelopes of Globular Clusters. II. NGC 1851, NGC 5824 and NGC 1261
• The Evolution of Copper in the Globular Cluster Omega Centauri
• Carbon in Red Giants in Globular Clusters and Dwarf Spheroidal Galaxies
• Formation of Multiple Populations in Globular Clusters: Another Possible Scenario
• The formation of the Milky Way halo and its dwarf satellites, a NLTE-1D abundance analysis. I. Homogeneous set of atmospheric parameters
• Manganese Abundances in Cluster and Field Stars
• The extended star formation history of omega Centauri
• Discovery of a Metal-Poor Field Giant with a Globular Cluster Second-Generation Abundance Pattern
• The Globular Cluster System of the Canis Major Dwarf Galaxy
• NGC 6535: the lowest mass Milky Way globular cluster with a Na-O anti-correlation? Cluster mass and age in the multiple population context
• The Gaia-ESO Survey: A globular cluster escapee in the Galactic halo
• Characterizing the High-Velocity Stars of RAVE: The Discovery of a Metal-Rich Halo Star Born in the Galactic Disk
• Multiple populations in Omega Centauri: a cluster analysis of spectroscopic data
• Chemodynamics of newly identified giants with globular cluster like abundance patterns in the bulge, disk, and halo of the Milky Way
• Europium abundances in F and G disk dwarfs
• An aluminium tool for multiple stellar generations in the globular clusters 47 Tuc and M 4
• Zinc abundances in Galactic bulge field red giants: implications for DLA systems
• Facing the problems on the determination of stellar temperatures and gravities: Galactic globular clusters
• Purveyors of fine halos: Re-assessing globular cluster contributions to the Milky Way halo build-up with SDSS-IV
• The chemical evolution of Omega Centauri's progenitor system
• A Minimum Dilution Scenario for Supernovae and Consequences for Extremely Metal-Poor Stars
• Galactic evolution of Copper in the light of NLTE computations
• The chemical composition of a regular halo globular cluster: NGC 5897
• The subgiant branch of omega Cen seen through high-resolution spectroscopy. I. The first stellar generation in omega Centauri?
• A New Test of Copper and Zinc Abundances in Late-Type Stars Using Ultraviolet Cu II and Zn II Lines
• Chemical characterization of the globular cluster NGC 5634 associated to the Sagittarius dwarf spheroidal galaxy
• Purveyors of fine halos. II. Chemodynamical association of halo stars with Milky Way globular clusters
• Insights into the chemical composition of the metal-poor Milky Way halo globular cluster NGC 6426
• The mass fraction of halo stars contributed by the disruption of globular clusters in the E-MOSAICS simulations
• Medium resolution spectroscopy in Omega Centauri: abundances of 400 subgiant and turn-off region
• Chemical and kinematic analysis of CN-strong Metal-poor Field Stars in LAMOST DR3
• The Most Metal-poor Stars in Omega Centauri (NGC 5139)
• High-velocity stars in the cores of globular clusters: The illustrative case of NGC 2808
• Chemical Compositions of Field and Globular Cluster RR~Lyrae Stars: II. omega Centauri
• The GALAH Survey: Chemically tagging the Fimbulthul stream to the globular cluster $\omega$ Centauri
• Mass Segregation and Tidal Tails of the Globular Cluster NGC 7492
• RAVE stars tidally stripped/ejected from $\omega$ Centauri globular cluster
• Mono-enriched stars and Galactic chemical evolution -- Possible biases in observations and theory
• NLTE analysis of copper lines in different stellar populations
• Formation of N-rich field stars in the high-density building blocks of the Galactic bulge
• A high-precision abundance analysis of the nuclear benchmark star HD 20
• Gaia DR2 orbital properties for field stars with globular cluster-like CN band strengths
• Evidence for a chemical enrichment coupling of globular clusters and field stars in the Fornax dSph
• Cu I resonance lines in turn-off stars of NGC 6752 and NGC 6397. Effects of granulation from CO5BOLD models
• An outer shade of Pal: Abundance analysis of the outer halo globular cluster Palomar 13
• Chemical composition of the outer halo globular cluster Palomar 15