| Download | - View final version: Variable stars in Local Group Galaxies: I. Tracing the early chemical enrichment and radial gradients in the Sculptor dSph with RR Lyrae stars (PDF, 1 MB)
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| DOI | Resolve DOI: https://doi.org/10.1093/mnras/stv2014 |
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| Author | Search for: Martínez-vázquez, C. E.; Search for: Monelli, M.; Search for: Bono, G.; Search for: Stetson, P. B.1; Search for: Ferraro, I.; Search for: Bernard, E. J.; Search for: Gallart, C.; Search for: Fiorentino, G.; Search for: Iannicola, G.; Search for: Udalski, A. |
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| Name affiliation | - National Research Council of Canada. Herzberg Astronomy and Astrophysics
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| Format | Text, Article |
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| Subject | Kstars: variables: RR Lyrae; galaxies: evolution; galaxies: individual: Sculptor dSph; Local Group; galaxies: stellar content |
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| Abstract | We identified and characterized the largest (536) RR Lyrae (RRL) sample in a Milky Way dSph satellite (Sculptor) based on optical photometry data collected over ∼24 years. The RRLs display a spread in V-magnitude (∼0.35 mag) which appears larger than photometric errors and the horizontal branch (HB) luminosity evolution of a mono-metallic population. Using several calibrations of two different reddening free and metal independent period–Wesenheit relations we provide a new distance estimate μ = 19.62 mag (σμ = 0.04 mag) that agrees well with literature estimates. We constrained the metallicity distribution of the old population, using the MI period–luminosity relation, and we found that it ranges from −2.3 to −1.5 dex. The current estimate is narrower than suggested by low and intermediate spectroscopy of RGBs (Δ [Fe/H]≤ 1.5). We also investigated the HB morphology as a function of the galactocentric distance. The HB in the innermost regions is dominated by red HB stars and by RRLs, consistent with a more metal-rich population, while in the outermost regions it is dominated by blue HB stars and RRLs typical of a metal-poor population. Our results suggest that fast chemical evolution occurred in Sculptor, and that the radial gradients were in place at an early epoch. |
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| Publication date | 2015-12-01 |
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| Publisher | Oxford University Press |
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| In | |
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| Language | English |
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| Peer reviewed | Yes |
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| NPARC number | 23001711 |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction |
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| Record identifier | 918adfc7-d2b4-4cff-805f-986ed484d990 |
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| Record created | 2017-03-21 |
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| Record modified | 2020-05-30 |
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