Detailed Chemical Abundances in NGC 5824: Another Metal-Poor Globular Cluster with Internal Heavy Element Abundance Variations

Abstract

We present radial velocities, stellar parameters, and detailed abundances of 39 elements derived from high-resolution spectroscopic observations of red giant stars in the luminous, metal-poor globular cluster NGC 5824. We observe 26 stars in NGC 5824 using the Michigan/Magellan Fiber System (M2FS) and two stars using the Magellan Inamori Kyocera Echelle (MIKE) spectrograph. We derive a mean metallicity of [Fe/H]=-1.94+/-0.02 (statistical) +/-0.10 (systematic). The metallicity dispersion of this sample of stars, 0.08 dex, is in agreement with previous work and does not exceed the expected observational errors. Previous work suggested an internal metallicity spread only when fainter samples of stars were considered, so we cannot exclude the possibility of an intrinsic metallicity dispersion in NGC 5824. The M2FS spectra reveal a large internal dispersion in [Mg/Fe], 0.28 dex, which is found in a few other luminous, metal-poor clusters. [Mg/Fe] is correlated with [O/Fe] and anti-correlated with [Na/Fe] and [Al/Fe]. There is no evidence for internal dispersion among the other alpha- or Fe-group abundance ratios. Twenty-five of the 26 stars exhibit a n-capture enrichment pattern dominated by r-process nucleosynthesis ([Eu/Fe]=+0.11+/-0.12; [Ba/Eu]=-0.66+/-0.05). Only one star shows evidence of substantial s-process enhancement ([Ba/Fe]=+0.56+/-0.12; [Ba/Eu]=+0.38+/-0.14), but this star does not exhibit other characteristics associated with s-process enhancement via mass-transfer from a binary companion. The Pb and other heavy elements produced by the s-process suggest a timescale of no more than a few hundred Myr for star formation and chemical enrichment, like the complex globular clusters M2, M22, and NGC 5286.

arXiv commentAccepted for publication in MNRAS. (26 pages, 18 figures, 9 tables including online data)

References in corpus (134)

• The chemical composition of the Sun
• Resolved Massive Star Clusters in the Milky Way and its Satellites: Brightness Profiles and a Catalogue of Fundamental Parameters
• An absolutely calibrated effective temperature scale from the InfraRed Flux Method
• A Triple Main Sequence in the Globular Cluster NGC 2808
• Optimal Techniques in Two-dimensional Spectroscopy: Background Subtraction for the 21st Century
• Na-O Anticorrelation and HB. VIII. Proton-capture elements and metallicities in 17 globular clusters from UVES spectra
• The Extremely Metal-Poor, Neutron-Capture-Rich Star CS 22892-052: A Comprehensive Abundance Analysis
• The O-Na and Mg-Al Anticorrelations in Turn-Off and early Subgiants in Globular Clusters
• Properties of stellar generations in Globular Clusters and relations with global parameters
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. I. Overview of the Project and Detection of Multiple Stellar Populations
• Carbon Enhanced Metal-Poor Stars. I. Chemical Compositions of 26 Stars
• A Search for Stars of Very Low Metal Abundance. VI. Detailed Abundances of 313 Metal-Poor Stars
• The ACS Survey of Galactic Globular Clusters. XII. Photometric Binaries along the Main-Sequence
• The extreme r-element rich, iron-poor halo giant CS31082-001: Implications for the r-process site(s) and radioactive cosmochronology
• Metallicities on the Double Main Sequence of omega Centauri Imply Large Helium Enhancement
• Non-LTE calculations for neutral Na in late-type stars using improved atomic data
• Sagittarius: The Nearest Dwarf Galaxy
• Chemical Abundances for 855 Giants in the Globular Cluster Omega Centauri (NGC 5139)
• Evolution, nucleosynthesis and yields of AGB stars at different metallicities (III): intermediate mass models, revised low mass models and the ph-FRUITY interface
• The Chemical Composition and Age of the Metal-Poor Halo Star BD +17^\circ 3248
• Carbon-Enhanced Metal-Poor Star Frequencies in the Galaxy: Corrections for the Effect of Evolutionary Status on Carbon Abundances
• The Abundances of Neutron Capture Species in the Very Metal-Poor Globular Cluster M15: An Uniform Analysis of RGB and RHB Stars
• Star-to-Star Abundance Variations among Bright Giants in the Mildly Metal-Poor Globular Cluster M4
• HST color-magnitude diagrams of 74 galactic globular clusters in the HST F439W and F555W bands
• Signatures of intrinsic Li depletion and Li-Na anti-correlation in the metal-poor globular cluster NGC6397
• The s-Process in Low Metallicity Stars. II. Interpretation of High-Resolution Spectroscopic Observations with AGB models
• Near-UV Observations of HD221170: New Insights into the Nature of r-Process-Rich Stars
• The second and third parameters of the Horizontal Branch in Globular Clusters
• Globular Clusters with Tidal Tails: Deep Two-Color Star Counts
• Detailed abundances of a large sample of giant stars in M 54 and in the Sagittarius nucleus
• The nucleus of the Sagittarius dSph galaxy and M54: a window on the process of galaxy nucleation
• A holistic approach to carbon-enhanced metal-poor stars
• Non-standard s process in low metallicity massive rotating stars
• New Rare Earth Element Abundance Distributions for the Sun and Five r-Process-Rich Very Metal-Poor Stars
• The s process in massive stars at low metallicity. Effect of primary N14 from fast rotating stars
• The two metallicity groups of the globular cluster M22: a chemical perspective
• New Analyses of Star-to-Star Abundance Variations Among Bright Giants in the Mildly Metal-Poor Globular Cluster M5
• Photometric signatures of multiple stellar populations in Galactic globular clusters
• The Chemical Composition Contrast between M3 and M13 Revisited: New Abundances for 28 Giant Stars in M3
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. III. A quintuple stellar population in NGC2808
• The Ubiquity of the Rapid Neutron-Capture Process
• A WFC3/HST view of the three stellar populations in the Globular Cluster NGC6752
• Tuning the Clock: Uranium and Thorium Chronometers Applied to CS 31082-001
• Improved Laboratory Transition Probabilities for Neutral Chromium and Re-determination of the Chromium Abundance for the Sun and Three Stars
• Multiple stellar populations in the globular cluster NGC 1851
• An abundance analysis of bright giants in the globular cluster NGC 1851
• HE 1327-2326, an unevolved star with [Fe/H]<-5.0. II. New 3D-1D corrected abundances from a VLT/UVES spectrum
• Iron and s-elements abundance variations in NGC5286: comparison with anomalous globular clusters and Milky Way satellites
• Detection of Elements at All Three r-process Peaks in the Metal-Poor Star HD 160617
• A double stellar generation in the Globular Cluster NGC6656 (M 22). Two stellar groups with different iron and s-process element abundance
• Abundances in giant stars of the globular cluster NGC 6752
• News from the Galactic suburbia: the chemical composition of the remote globular cluster NGC 2419
• Probing the Neutron-Capture Nucleosynthesis History of Galactic Matter
• Hubble Space Telescope reveals multiple Sub-Giant Branch in eight Globular Clusters
• 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
• Exploring Anticorrelations and Light Element Variations in Northern Globular Clusters Observed by the APOGEE Survey
• Mg isotopic ratios in giant stars of the globular cluster NGC 6752
• New Hubble Space Telescope Observations of Heavy Elements in Four Metal-Poor Stars
• Iron and neutron-capture element abundance variations in the globular cluster M2 (NGC 7089)
• M22: A [Fe/H] Abundance Range Revealed
• Improved Ti II log(gf) Values and Abundance Determinations in the Photospheres of the Metal-Poor Star HD 84937
• The Bizarre Chemical Inventory of NGC 2419, An Extreme Outer Halo Globular Cluster
• HST Observations of Heavy Elements in Metal-Poor Galactic Halo Stars
• Carbon-Enhanced Metal-Poor Stars. III. Main-Sequence Turn-Off Stars from the SDSS/SEGUE Sample
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. II. The seven stellar populations of NGC7089 (M2)
• Spectroscopy Unveils the Complex Nature of Terzan 5
• The End of Nucleosynthesis: Production of Lead and Thorium in the Early Galaxy
• Abundances for a large sample of red giants in NGC 1851: hints for a merger of two clusters?
• Stellar Chemical Abundances: In Pursuit of the Highest Achievable Precision
• Fe I Oscillator Strengths for the Gaia-ESO Survey
• Towards stellar effective temperatures and diameters at one per cent accuracy for future surveys
• Improved Ni I log(gf) Values and Abundance Determinations in the Photospheres of the Sun and Metal-poor Star HD 84937
• Improved Laboratory Transition Probabilities for Er II and Applications to the Erbium Abundances of the Sun and Five r-Process Rich, Metal-Poor Stars
• A 500 Parsec Halo Surrounding the Galactic Globular NGC 1851
• Ceci n'est pas a globular cluster: the metallicity distribution of the stellar system Terzan 5
• Detailed abundances of Red Giants in the Globular Cluster NGC~1851: C+N+O and the Origin of Multiple Populations
• A new abundance scale for the globular cluster 47 Tuc
• Na-O Anticorrelation and HB. II. The Na-O anticorrelation in the globular cluster NGC 6752
• The r-process in the early Galaxy
• High Precision Differential Abundance Measurements in Globular Clusters: Chemical Inhomogeneities in NGC 6752
• Elemental abundances and classification of CEMP stars
• Hubble Space Telescope Observations of an Outer Field in Omega Centauri: A Definitive Helium Abundance
• The Terzan 5 puzzle: discovery of a third, metal-poor component
• Neutral oxygen spectral line formation revisited with new collisional data: large departures from LTE at low metallicity
• A Spectroscopic Analysis of the Galactic Globular Cluster NGC 6273 (M19)
• The double sub-giant branch of NGC 6656 (M22): a chemical characterization
• Heavy element abundances in giant stars of the globular clusters M4 and M5
• Ba stars and other binaries in first and second generation stars in globular clusters
• The Origins of Two Classes of Carbon-Enhanced, Metal-Poor Stars
• NGC 2419 -- Another Remnant of Accretion by the Milky Way
• NGC 362: another globular cluster with a split red giant branch
• The extreme chemistry of multiple stellar populations in the metal-poor globular cluster NGC 4833
• Nine New Metal-Poor Stars on the Subgiant and Red Horizontal Branches with High Levels of r-process Enhancement
• Helium and Multiple Populations in the Massive Globular Cluster NGC6266 (M62)
• Primordial r-process Dispersion in Metal-Poor Globular Clusters
• On the Abundance of Potassium in Metal-Poor Stars
• New Abundance Determinations of Cadmium, Lutetium, and Osmium in the r-process Enriched Star BD+173248
• Ba & Eu Abundances in M15 giant stars
• Non-LTE effects on the lead and thorium abundance determinations for cool stars
• Improved V II log($gf$) Values, Hyperfine Structure Constants, and Abundance Determinations in the Photospheres of the Sun and Metal-poor Star HD 84937
• A chemical trompe-l'œil: no iron spread in the globular cluster M22
• The halo+cluster system of the Galactic globular cluster NGC1851
• Heavy elements in Globular Clusters: the role of AGB stars
• Rubidium and lead abundances in giant stars of the globular clusters M4 and M5
• Super AGB and AGB evolution and the chemical inventory in NGC 2419
• Characterizing the Heavy Elements in Globular Cluster M22 and an Empirical s-process Abundance Distribution Derived from the Two Stellar Groups
• NGC 2419: a large and extreme second generation in a currently undisturbed cluster
• Potassium: a new actor on the globular cluster chemical evolution stage. The case of NGC 2808
• Binary Blue Metal-Poor Stars: Evidence for AGB Mass Transfer
• Detection of the Second r-process Peak Element Tellurium in Metal-Poor Stars
• Neutron-capture elements in the metal-poor globular cluster M15
• A search for stellar tidal debris of defunct dwarf galaxies around globular clusters in the inner Galactic halo
• Homogeneous Metallicities and Radial Velocities for Galactic Globular Clusters
• The origin of the spurious iron spread in the globular cluster NGC 3201
• Chemical abundances in bright giants of the globular cluster M62 (NGC 6266)
• Spectroscopic Signatures of Extra-Tidal Stars Around the Globular Clusters NGC 6656 (M22), NGC 3201 and NGC 1851 from RAVE
• Detailed Abundance Analysis of the Brightest Star in Segue 2, the Least Massive Galaxy
• Three discrete groups with homogeneous chemistry along the red giant branch in the globular cluster NGC 2808
• NGC 5824: a luminous outer halo globular cluster with an intrinsic abundance spread
• Potassium in globular cluster stars: comparing normal clusters to the peculiar cluster NGC 2419
• Spectroscopic Binaries in Globular Clusters. II. A Search for Long-Period Binaries in M22
• A comprehensive chemical abundance study of the outer halo globular cluster M 75
• The chemical composition of a regular halo globular cluster: NGC 5897
• Chemical Abundances for Evolved Stars in M5: Lithium through Thorium
• Detailed Abundances of 15 Stars in the Metal-Poor Globular Cluster NGC 4833
• No Heavy Element Dispersion in the Globular Cluster M92
• Chemical enrichment mechanisms in Omega Centauri: clues from neutron-capture elements
• A low surface brightness halo surrounding the globular cluster NGC 5694
• The Gaia-ESO Survey: Detailed Abundances in the Metal-poor Globular Cluster NGC 4372
• A differential chemical element analysis of the metal poor Globular Cluster NGC 6397
• The s-Process Enrichment of the Globular Clusters M4 and M22
• New cluster members and halo stars of the Galactic globular cluster NGC 1851
• High-Resolution Spectroscopy of Extremely Metal-Poor Stars from SDSS/SEGUE: II. Binary Fraction
• A comparative study of two 47 Tuc giant stars with different s-process enrichment

Cited by in corpus (38)

• What is a globular cluster? An observational perspective
• N-body modeling of globular clusters: Masses, mass-to-light ratios and intermediate-mass black holes
• Complete element abundances of nine stars in the r-process galaxy Reticulum II
• Detailed Chemical Abundances in the r-Process-Rich Ultra-Faint Dwarf Galaxy Reticulum 2
• Dynamical Relics of the Ancient Galactic Halo
• $S^5$: The Orbital and Chemical Properties of One Dozen Stellar Streams
• The R-Process Alliance: A Comprehensive Abundance Analysis of HD 222925, a Metal-Poor Star with an Extreme R-Process Enhancement of [Eu/H] = -0.14
• Formation of Globular Cluster Candidates in Merging Proto-galaxies at High Redshift: A View from the FIRE Cosmological Simulations
• The Accreted Nuclear Clusters of the Milky Way
• The Outer Envelopes of Globular Clusters. II. NGC 1851, NGC 5824 and NGC 1261
• NGC 6535: the lowest mass Milky Way globular cluster with a Na-O anti-correlation? Cluster mass and age in the multiple population context
• Can Neutron-Star Mergers Explain the r-process Enrichment in Globular Clusters?
• Metallicity variations in the Type II globular cluster NGC6934
• On the R-Process Enrichment of Dwarf Spheroidal Galaxies
• Multiple stellar populations in the globular cluster M3 (NGC 5272): a Strömgren perspective
• Revealing the Complicated Story of the Cetus Stream with StarGO
• Insights into the chemical composition of the metal-poor Milky Way halo globular cluster NGC 6426
• The R-Process Alliance: Chemical Abundances for a Trio of R-Process-Enhanced Stars -- One Strong, One Moderate, One Mild
• The R-Process Alliance: J1521-3538, a very metal-poor, extremely r-process-enhanced star with [Eu/Fe]=+2.2, and the class of r-III stars
• Is NGC 5824 the Core of the Progenitor of the Cetus Stream?
• Chemical Complexity in the Eu-enhanced Monometallic Globular Cluster NGC 5986
• The chemical composition of NGC5824, a globular cluster without iron spread but with an extreme Mg-Al anticorrelation
• Light and Heavy Element Abundance Variations in the Outer Halo Globular Cluster NGC 6229
• High Resolution Optical Spectroscopy of Stars in the Sylgr Stellar Stream
• Excess of Ca (and Sc) produced in globular cluster multiple populations: a first census in 77 Galactic globular clusters
• Confirming the intrinsic abundance spread in the globular cluster NGC 6273 (M 19) with calcium triplet spectroscopy
• Galactic Pal-eontology: Abundance Analysis of the Disrupting Globular Cluster Palomar 5
• An outer shade of Pal: Abundance analysis of the outer halo globular cluster Palomar 13
• A Photometric Study of the Outer Halo Globular Cluster NGC 5824
• Inference of multi-channel r-process element enrichment in the Milky Way using binary neutron star merger observations
• The Implications of Ultra-Faint Dwarf Galaxy Reticulum II on the Common Envelope Jets Supernova r-process Scenario
• Chemical composition of the outer halo globular cluster Palomar 15
• New sub-grouping of multiple stellar populations in NGC 2808 based on low-resolution spectroscopy
• Magellan/M2FS Spectroscopy of Galaxy Clusters: Stellar Population Model and Application to Abell 267
• Globular Cluster Intrinsic Iron Abundance Spreads: I. Catalog
• Neutron-capture elements in a sample of field metal-poor N-rich dwarfs
• Mock Observations of Multiple Stellar Populations in Tidal Streams of Palomar 5 for the Chinese Space Station Survey Telescope
• A Main Sequence CH-star in the globular cluster M55 (NGC 6809)