| Téléchargement | - Voir la version finale : Variable stars in Local Group Galaxies: I. Tracing the early chemical enrichment and radial gradients in the Sculptor dSph with RR Lyrae stars (PDF, 1.1 Mio)
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| DOI | Trouver le DOI : https://doi.org/10.1093/mnras/stv2014 |
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| Auteur | Rechercher : Martínez-vázquez, C. E.; Rechercher : Monelli, M.; Rechercher : Bono, G.; Rechercher : Stetson, P. B.1; Rechercher : Ferraro, I.; Rechercher : Bernard, E. J.; Rechercher : Gallart, C.; Rechercher : Fiorentino, G.; Rechercher : Iannicola, G.; Rechercher : Udalski, A. |
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| Affiliation | - Conseil national de recherches du Canada. Herzberg en astronomie et en astrophysique
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| Format | Texte, Article |
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| Sujet | Kstars: variables: RR Lyrae; galaxies: evolution; galaxies: individual: Sculptor dSph; Local Group; galaxies: stellar content |
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| Résumé | 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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| Date de publication | 2015-12-01 |
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| Maison d’édition | Oxford University Press |
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| Dans | |
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| Langue | anglais |
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| Publications évaluées par des pairs | Oui |
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| Numéro NPARC | 23001711 |
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| Exporter la notice | Exporter en format RIS |
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| Signaler une correction | Signaler une correction (s'ouvre dans un nouvel onglet) |
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| Identificateur de l’enregistrement | 918adfc7-d2b4-4cff-805f-986ed484d990 |
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| Enregistrement créé | 2017-03-21 |
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| Enregistrement modifié | 2020-05-30 |
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