Photometric characterization of multiple populations in star clusters: The impact of the first dredge-up

Abstract

The existence of star-to-star light-element abundance variations (multiple populations, MPs) in massive Galactic and extragalactic star clusters older than about 2 Gyr is by now well established. Photometry of red giant branch (RGB) stars has been and still is instrumental in enabling the detection and characterization of cluster MPs, through the appropriate choices of filters, colours and colour combinations, that are mainly sensitive to N and --to a lesser degree-- C stellar surface abundances. An important issue not yet properly addressed is that the translation of the observed widths of the cluster RGBs to abundance spreads must account for the effect of the first dredge-up on the surface chemical patterns, hence on the spectral energy distributions of stars belonging to the various MPs. We have filled this gap by studying theoretically the impact of the dredge-up on the predicted widths of RGBs in clusters hosting MPs. We find that for a given initial range of N abundances, the first dredge up reduces the predicted RGB widths in N-sensitive filters compared to the case when its effect on the stellar spectral energy distributions is not accounted for. This reduction is a strong function of age and has also a dependence on metallicity. The net effect is an underestimate of the initial N-abundance ranges from RGB photometry if the first dredge-up is not accounted for in the modelling, and also the potential determination of spurious trends of N-abundance spreads with age.

arXiv comment7 pages, 6 figures, MNRAS in press

References in corpus (40)

• A large stellar evolution database for population synthesis studies. I. Scaled solar models and isochrones
• Multiple populations in globular clusters. Lessons learned from the Milky Way globular clusters
• Multiple Stellar Populations in Globular Clusters
• The Dawes Review 2: Nucleosynthesis and stellar yields of low and intermediate-mass single stars
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. I. Overview of the Project and Detection of Multiple Stellar Populations
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. IX. The Atlas of Multiple Stellar Populations
• Spectroscopic and Photometric evidence of two stellar populations in the Galactic Globular Cluster NGC6121 (M4)
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. V. Constraints on Formation Scenarios
• What is a globular cluster? An observational perspective
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XVI. The helium abundance of multiple populations
• Photometric signatures of multiple stellar populations in Galactic globular clusters
• Abundances of C, N, O in slightly evolved stars in the globular clusters NGC 6397, NGC 6752 and 47 Tuc
• Looking outside the Galaxy: the discovery of chemical anomalies in 3 old Large Magellanic Cloud clusters
• The SUMO project I. A survey of multiple populations in globular clusters
• Nitrogen abundances in giant stars of the globular cluster NGC 6752
• Age as a Major Factor in the Onset of Multiple Populations in Stellar Clusters
• Multiple populations in globular clusters and their parent galaxies
• The Search for Multiple Populations in Magellanic Cloud Clusters II: The Detection of Multiple Populations in Three Intermediate-Age SMC Clusters
• Multiple populations in the old and massive Small Magellanic Cloud globular cluster NGC121
• Nitrogen abundances and multiple stellar populations in the globular clusters of the Fornax dSph
• Post first dredge-up [C/N] ratio as age indicator. Theoretical calibration
• On the primordial scenario for abundance variations within globular clusters. The isochrone test
• The Search for Multiple Populations in Magellanic Cloud Clusters III: No evidence for Multiple Populations in the SMC cluster NGC 419
• The Gaia-ESO survey: impact of extra-mixing on C- and N-abundances of giant stars
• Star Clusters in M31. V. Evidence for Self-Enrichment in Old M31 Clusters from Integrated Spectroscopy
• The search for multiple populations in Magellanic Clouds clusters - V. Correlation between cluster age and abundance spreads
• The Search for Multiple Populations in Magellanic Cloud Clusters I: Two Stellar Populations in the Small Magellanic Cloud Globular Cluster NGC 121
• Evidence for multiple populations in the intermediate age cluster Lindsay 1 in the SMC
• Photometric properties of stellar populations in Galactic globular clusters: the role of the Mg-Al anticorrelation
• Chemical abundances in the multiple sub-giant branch of 47 Tucanae: insights on its faint sub-giant branch component
• Four stellar populations and extreme helium variation in the massive outer-halo globular cluster NGC 2419
• NGC6362: the least massive globular cluster with chemically distinct multiple populations
• Spectroscopic detection of multiple populations in the ~2 Gyr old cluster Hodge 6 in the LMC
• Observing the products of stellar evolution in the old open cluster M67 with APOGEE
• IC4499 revised: spectro-photometric evidence of small light-element variations
• Hubble Space Telescope analysis of stellar populations within the globular cluster G1 (Mayall II) in M31
• Exploring the nature and synchronicity of early cluster formation in the Large Magellanic Cloud IV: Evidence for Multiple Populations in Hodge 11 and NGC 2210
• An Extragalactic Chromosome Map: The intermediate age SMC Cluster Lindsay 1
• Multiple Populations in Integrated Light Spectroscopy of Intermediate Age Clusters
• Detection of multiple stellar populations in extragalactic massive clusters with JWST

Cited by in corpus (13)

• Multiple populations in massive star clusters under the magnifying glass of photometry: Theory and tools
• Expanding the time domain of multiple populations: evidences of nitrogen variations in the ~1.5 Gyr old star cluster NGC 1783
• Chromosome maps of young LMC clusters: An additional case of coeval multiple populations
• Leveraging HST with MUSE: I. Sodium abundance variations within the 2 Gyr-old cluster NGC 1978
• On the Nitrogen variation in ~2 Gyr old massive star clusters in the Large Magellanic Cloud
• Accretion of sub-stellar companions as the origin of chemical abundance inhomogeneities in globular clusters
• Searching for globular cluster chemical anomalies on the main sequence of a young massive cluster
• APOGEE Detection of N-rich stars in the tidal tails of Palomar 5
• Leveraging HST with MUSE: II. Na-abundance variations in intermediate age star clusters
• Evidence of globular cluster abundance anomalies in the SMC intermediate-age cluster Kron 3
• Searching for Multiple Populations in the Integrated Light of the Young and Extremely Massive Clusters in the Merger Remnant NGC~7252
• New sub-grouping of multiple stellar populations in NGC 2808 based on low-resolution spectroscopy
• Role of host galaxy in the formation of multiple stellar populations: Analysis of NGC 1786 and NGC 1898