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http://hdl.handle.net/20.500.12386/25049
Title: | Probing the early chemical evolution of the Sculptor dSph with purely old stellar tracers | Authors: | Martínez-Vázquez, C. E. Monelli, Matteo Gallart, C. Bono, Giuseppe Bernard, E. J. Stetson, P. B. FERRARO, Ivan Walker, A. R. DALL'ORA, Massimo FIORENTINO, Giuliana IANNICOLA, GIACINTO |
Issue Date: | 2016 | Journal: | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | Number: | 461 | Issue: | 1 | First Page: | L41 | Abstract: | We present the metallicity distribution of a sample of 471 RR Lyrae (RRL) stars in the Sculptor dSph, obtained from the I-band period-luminosity relation. It is the first time that the early chemical evolution of a dwarf galaxy is characterized in such a detailed and quantitative way, using photometric data alone. We find a broad metallicity distribution (full width at half-maximum equals to 0.8 dex) that is peaked at [Fe/H] ≃ -1.90 dex, in excellent agreement with literature values obtained from spectroscopic data. Moreover, we are able to directly trace the metallicity gradient out to a radius of ∼55 arcmin. We find that in the outer regions (r > ∼32 arcmin) the slope of the metallicity gradient from the RRLs (-0.025 dex arcmin<SUP>-1</SUP>) is comparable to the literature values based on red giant (RG) stars. However, in the central part of Sculptor, we do not observe the latter gradients. This suggests that there is a more metal-rich and/or younger population in Sculptor that does not produce RRLs. This scenario is strengthened by the observation of a metal-rich peak in the metallicity distribution of RG stars by other authors, which is not present in the metallicity distribution of the RRLs within the same central area. | URI: | http://hdl.handle.net/20.500.12386/25049 | URL: | https://academic.oup.com/mnrasl/article/461/1/L41/2589600 | ISSN: | 0035-8711 | DOI: | 10.1093/mnrasl/slw093 | Bibcode ADS: | 2016MNRAS.461L..41M | Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista |
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