An investigation of C, N and Na abundances in red giant stars of the Sculptor dwarf spheroidal galaxy

Abstract

The origin of the star-to-star abundance variations found for the light elements in Galactic globular clusters (GGCs) is not well understood, which is a significant problem for stellar astrophysics. While the light element abundance variations are very common in globular clusters, they are comparatively rare in the Galactic halo field population. However, little is known regarding the occurrence of the abundance anomalies in other environments such as that of dwarf spheroidal (dSph) galaxies. Consequently, we have investigated the anti-correlation and bimodality of CH and CN band strengths, which are markers of the abundance variations in GGCs, in the spectra of red giants in the Sculptor dwarf spheroidal galaxy. Using spectra at the Na~D lines, informed by similar spectra for five GGCs (NGC 288, 1851, 6752, 6809 and 7099), we have also searched for any correlation between CN and Na in the Sculptor red giant sample. Our results indicate that variations analogous to those seen in GGCs are not present in our Sculptor sample. Instead, we find a weak positive correlation between CH and CN, and no correlation between Na and CN. We also reveal a deficiency in [Na/Fe] for the Sculptor stars relative to the values in GGCs, a result which is consistent with previous work for dSph galaxies. The outcomes reinforce the apparent need for a high stellar density environment to produce the light element abundance variations.

arXiv comment24 pages, 17 figures, 8 tables

References in corpus (56)

• Gaia Data Release 2. Summary of the contents and survey properties
• SparsePak: A Formatted Fiber Field Unit for The WIYN Telescope Bench Spectrograph. I. Design, Construction, and Calibration
• Fast rotating massive stars and the origin of the abundance patterns in galactic globular clusters
• Multiple Stellar Populations in Globular Clusters
• A Universal Mass Profile for Dwarf Spheroidal Galaxies?
• Na-O Anticorrelation and HB. VIII. Proton-capture elements and metallicities in 17 globular clusters from UVES spectra
• The effective temperature scale of FGK stars. II. Teff : color : [Fe/H] calibrations
• 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
• VLT/UVES Abundances in Four Nearby Dwarf Spheroidal Galaxies: I. Nucleosynthesis and Abundance Ratios
• Predictions for self-pollution in globular cluster stars
• Carbon-Enhanced Metal-Poor Star Frequencies in the Galaxy: Corrections for the Effect of Evolutionary Status on Carbon Abundances
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. V. Constraints on Formation Scenarios
• A helium spread among the main sequence stars in NGC 2808
• Velocity Dispersion Profiles of Seven Dwarf Spheroidal Galaxies
• The Abundances of Neutron Capture Species in the Very Metal-Poor Globular Cluster M15: An Uniform Analysis of RGB and RHB Stars
• Super-Massive Stars as a Source of Abundance Anomalies of Proton-Capture Elements in Globular Clusters
• Stellar Velocities in the Carina, Fornax, Sculptor and Sextans dSph Galaxies: Data from the Magellan/MMFS Survey
• The NIR Ca II triplet at low metallicity - Searching for extremely low-metallicity stars in classical dwarf galaxies
• A high resolution VLT/FLAMES study of individual stars in the centre of the Fornax dwarf spheroidal galaxy
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XVI. The helium abundance of multiple populations
• Analysis and calibration of CaII triplet spectroscopy of Red Giant Branch stars from VLT/FLAMES observations
• Chemical tagging with APOGEE: Discovery of a large population of N-rich stars in the inner Galaxy
• 'Sculptor'-ing the Galaxy? The Chemical Compositions of Red Giants in the Sculptor Dwarf Spheroidal Galaxy
• Multi-Element Abundance Measurements from Medium-Resolution Spectra. II. Catalog of Stars in Milky Way Dwarf Satellite Galaxies
• Chemistry of the Sagittarius Dwarf Galaxy: a Top-Light IMF, Outflows and the R-Process
• A WFC3/HST view of the three stellar populations in the Globular Cluster NGC6752
• The Star Formation & Chemical Evolution History of the Sculptor Dwarf Spheroidal Galaxy
• Chemical Enrichment in the Faintest Galaxies: the Carbon and Iron Abundance Spreads in the Boötes I Dwarf Spheroidal Galaxy and the Segue 1 System
• A unique model for the variety of multiple populations formation(s) in globular clusters: a temporal sequence
• Abundances of C, N, O in slightly evolved stars in the globular clusters NGC 6397, NGC 6752 and 47 Tuc
• Building the Galactic halo from globular clusters: evidence from chemically unusual red giants
• Multi-Element Abundance Measurements from Medium-Resolution Spectra. I. The Sculptor Dwarf Spheroidal Galaxy
• Helium enhanced stars and multiple populations along the horizontal branch of NGC2808: direct spectroscopic measurements
• Light nuclei in galactic globular clusters : constraints on the self-enrichment scenario from nucleosynthesis
• Nitrogen abundances in giant stars of the globular cluster NGC 6752
• Using the Ca II Triplet to Trace Abundance Variations in Individual Red Giant Branch stars in Three Nearby Galaxies
• Chemical Composition of Extremely Metal-Poor Stars in the Sextans Dwarf Spheroidal Galaxy
• The Araucaria Project. The Distance to the Sculptor dwarf spheroidal galaxy from infrared photometry of RR Lyrae stars
• VLT/FLAMES spectroscopy of red giant branch stars in the Fornax dwarf spheroidal galaxy
• On the Origin of the High Helium Sequence in $\omega$ Centauri
• APOGEE Chemical Abundances of Globular Cluster Giants in the Inner Galaxy
• APOGEE Chemical Abundances of the Sagittarius Dwarf Galaxy
• On the primordial scenario for abundance variations within globular clusters. The isochrone test
• Chemical Abundance Analysis of the Extremely Metal-Poor Star HE 1300+0157
• Carbon in Red Giants in Globular Clusters and Dwarf Spheroidal Galaxies
• The depletion of carbon by extra mixing in metal-poor giants
• CNO enrichment by rotating AGB stars in globular clusters
• Evidence for multiple populations in the intermediate age cluster Lindsay 1 in the SMC
• The Populations of Carina. II. Chemical Enrichment
• The Absence of Extra-Tidal Structure in the Sculptor Dwarf Spheroidal Galaxy
• Infrared Echelle Spectroscopy of Palomar6 and M71
• Carbon and nitrogen abundances of individual stars in the Sculptor dwarf spheroidal galaxy
• Kron 3: a fourth intermediate age cluster in the SMC with evidence of multiple populations
• Scl-1013644: a CEMP-s star in the Sculptor Dwarf Spheroidal Galaxy

Cited by in corpus (9)

• The chemical composition of globular clusters in the Local Group
• Purveyors of fine halos. II. Chemodynamical association of halo stars with Milky Way globular clusters
• The 3D non-LTE solar nitrogen abundance from atomic lines
• Formation of N-rich field stars in the high-density building blocks of the Galactic bulge
• A 3D view of dwarf galaxies with Gaia and VLT/FLAMES I. The Sculptor dwarf spheroidal
• $S^5$: The destruction of a bright dwarf galaxy as revealed by the chemistry of the Indus stellar stream
• Hubble Space Telescope photometry of multiple stellar populations in the inner parts of NGC 2419
• Evidence of globular cluster abundance anomalies in the SMC intermediate-age cluster Kron 3
• Different Sodium enhancements among multiple populations of Milky Way globular clusters