A chromosome map to unveil stellar populations with different magnesium abundances. The case of Omega Centauri

Abstract

Historically, photometry has been largely used to identify stellar populations (MPs) in Globular Clusters (GCs) by using diagrams that are based on colours and magnitudes that are mostly sensitive to stars with different metallicities or different abundances of helium, carbon, nitrogen and oxygen. In particular, the pseudo two-colour diagram called chromosome map (ChM), allowed the identification and the characterization of MPs in about 70 GCs by using appropriate filters of the Hubble Space Telescope (HST) that are sensitive to the stellar content of He, C, N, O and Fe. We use here high-precision HST photometry from F275W, F280N, F343N, F373N, and F814W images of Omega Centauri to investigate its MPs. We introduce a new ChM whose abscissa and ordinate are mostly sensitive to stellar populations with different magnesium and nitrogen, respectively, in monometallic GCs. This ChM is effective in disentangling the MPs based on their Mg chemical abundances, allowing us to explore, for the first time, possible relations between the production of these elemental species for large samples of stars in GCs. By comparing the colours of the distinct stellar populations with the colours obtained from appropriate synthetic spectra we provide 'photometric-like' estimates of the chemical composition of each population. Our results show that, in addition to first generation (1G) stars, the metal-poor population of Omega Centauri hosts four groups of second-generation stars with different [N/Fe], namely, 2GA--D. 2GA stars share nearly the same [Mg/Fe] as the 1G, whereas 2GB, 2GC and 2GD stars are Mg depleted by ~0.15, ~0.25 and ~0.45 dex, respectively. We provide evidence that the metal-intermediate populations host stars with depleted [Mg/Fe].

arXiv comment15 pages, 11 figures, accepted for publication in MNRAS

References in corpus (75)

• The Dartmouth Stellar Evolution Database
• Multiple populations in globular clusters. Lessons learned from the Milky Way globular clusters
• Na-O Anticorrelation and HB. VII. The chemical composition of first and second-generation stars in 15 globular clusters from GIRAFFE spectra
• Fast rotating massive stars and the origin of the abundance patterns in galactic globular clusters
• A Triple Main Sequence in the Globular Cluster NGC 2808
• Multiple Stellar Populations in Globular Clusters
• Formation and Dynamical Evolution of Multiple Stellar Generations in Globular Clusters
• Omega Centauri: The Population Puzzle Goes Deeper
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. IX. The Atlas of Multiple Stellar Populations
• The ACS Survey of Galactic Globular Clusters. IX. Horizontal Branch Morphology and the Second Parameter Phenomenon
• Predictions for self-pollution in globular cluster stars
• An ACS Survey of Globular Clusters V: Star Catalog for Each Cluster
• Spectroscopic and Photometric evidence of two stellar populations in the Galactic Globular Cluster NGC6121 (M4)
• Multiple Stellar Populations in the Globular Cluster omega Centauri as Tracers of a Merger Event
• Chemical Abundances for 855 Giants in the Globular Cluster Omega Centauri (NGC 5139)
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. V. Constraints on Formation Scenarios
• Super-Massive Stars as a Source of Abundance Anomalies of Proton-Capture Elements in Globular Clusters
• Helium variation due to self-pollution among Globular Cluster stars: consequences on the horizontal branch morphology
• Early Disc Accretion as the Origin of Abundance Anomalies in Globular Clusters
• Multiple stellar populations in 47 Tucanae
• On the self-enrichment scenario of galactic globular clusters: Constraints on the IMF
• Detailed abundances of a large sample of giant stars in M 54 and in the Sagittarius nucleus
• An Empirical Pixel-Based Correction for Imperfect CTE. I. HST's Advanced Camera for Surveys
• Concurrent formation of supermassive stars and globular clusters: implications for early self-enrichment
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XVI. The helium abundance of multiple populations
• New evidence for the complex struscture of the RGB of Omega Cen
• 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
• Astrometry and photometry with HST WFC3. II. Improved geometric-distortion corrections for 10 filters of the UVIS channel
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. III. A quintuple stellar population in NGC2808
• Transforming observational data and theoretical isochrones into the ACS/WFC Vega-mag system
• A unique model for the variety of multiple populations formation(s) in globular clusters: a temporal sequence
• An abundance analysis of bright giants in the globular cluster NGC 1851
• Iron and s-elements abundance variations in NGC5286: comparison with anomalous globular clusters and Milky Way satellites
• Homogeneous Analysis of Globular Clusters from the APOGEE Survey with the BACCHUS Code. II. The Southern Clusters and Overview
• A double stellar generation in the Globular Cluster NGC6656 (M 22). Two stellar groups with different iron and s-process element abundance
• Sodium-oxygen anticorrelation and neutron capture elements in Omega Centauri stellar populations
• Exploring Anticorrelations and Light Element Variations in Northern Globular Clusters Observed by the APOGEE Survey
• The State-of-the-Art HST Astro-Photometric Analysis of the core of $\omega$ Centauri. I. The Catalog
• Iron and neutron-capture element abundance variations in the globular cluster M2 (NGC 7089)
• M22: A [Fe/H] Abundance Range Revealed
• Nitrogen abundances in giant stars of the globular cluster NGC 6752
• The Abundance Spread Among Giants and Subgiants in the Globular Cluster Omega Centauri
• Metallicities, relative ages and kinematics of stellar populations in omega Centauri
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XIX. A Chemical Tagging of the Multiple Stellar Populations Over the Chromosome Maps
• New HST WFC3/UVIS observations augment the stellar-population complexity of omega Centauri
• Deep FORS1 observations of the double Main Sequence of omega Centauri
• Five groups of red giants with distinct chemical composition in the globular cluster NGC 2808
• The C+N+O abundance of Omega Centauri giant stars: implications on the chemical enrichment scenario and the relative ages of different stellar populations
• Hubble Tarantula Treasury Project. III. Photometric Catalog and Resulting Constraints on the Progression of Star Formation in the 30 Doradus Region
• Multiple populations in globular clusters and their parent galaxies
• Astrometry and photometry with HST-WFC3. I. Geometric distortion corrections of F225W, F275W, F336W bands of the UVIS-channel
• A homogeneous analysis of globular clusters from the APOGEE survey with the BACCHUS code. I. The Northern clusters
• Discovery of an anomalous Sub Giant Branch in the Color Magnitude Diagram of omega Centauri
• A Spectroscopic Analysis of the Galactic Globular Cluster NGC 6273 (M19)
• Sodium content as a predictor of the advanced evolution of globular cluster stars
• Finding Forming Globular Clusters at High Redshifts
• The infrared eye of the Wide-Field Camera 3 on the Hubble Space Telescope reveals multiple main sequences of very low-mass stars in NGC 2808
• The HST Large Program on Omega Centauri. I. Multiple stellar populations at the bottom of the main sequence probed in NIR-Optical
• Formation of Second Generation Stars in Globular Clusters
• Revisiting nucleosynthesis in globular clusters: the case of NGC 2808 and the role of He and K
• Multiple populations in Omega Centauri: a cluster analysis of spectroscopic data
• The mosaic multiple stellar populations in $\omega$ Centauri : the Horizontal Branch and the Main Sequence
• Photometry and spectroscopy of multiple populations along the AGB of NGC2808 and NGC6121 (M4)
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters - XII. The RGB Bumps of multiple stellar populations
• A Chemical Composition Survey of the Iron-Complex Globular Cluster NGC 6273 (M 19)
• The HST Large Programme on NGC6752. II. Multiple populations at the bottom of the main sequence probed in NIR
• Four stellar populations and extreme helium variation in the massive outer-halo globular cluster NGC 2419
• Metallicity variations in the Type II globular cluster NGC6934
• Magnesium Isotope Ratios in omega Centauri Red Giants
• Chemical analysis of Asymptotic Giant Branch stars in M62
• Sodium abundances of AGB and RGB stars in galactic globular clusters I. Analysis and results of NGC 2808
• The discovery of a Li-Na-rich giant star in Omega Centauri: formed from the pure ejecta of super-AGB stars?
• Chemical composition of stellar populations in Omega Centauri

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• Light Elements in the Universe
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• oMEGACat III. Multi-band photometry and metallicities reveal spatially well-mixed populations within $\omega$ Centauri's half-light radius
• Searching for multiple populations in star clusters using the China Space Station Telescope
• Models for Metal-Poor Stars with Different Initial Abundances of C, N, O, Mg, and Si. II. Application to the Colour-Magnitude Diagrams of the Globular Clusters 47 Tuc, NGC 6362, M5, M3, M55, and M92
• First observational evidence of a relation between globular clusters' internal rotation and stellar masses
• On the maximum helium content of multiple populations in the globular cluster NGC6752
• UVIT-HST-Gaia-VISTA study of KRON 3 in the Small Magellanic Cloud: A cluster with an extended red clump in UV