Galactic evolution of sulphur as traced by globular clusters
dc.contributor.author | Kacharov, N. | |
dc.contributor.author | Koch, A. | |
dc.contributor.author | Caffau, E. | |
dc.contributor.author | Sbordone, L. | |
dc.date.accessioned | 2024-01-10T13:13:14Z | |
dc.date.available | 2024-01-10T13:13:14Z | |
dc.date.issued | 2015 | |
dc.description.abstract | Context. Sulphur is an important volatile a element, but its role in the Galactic chemical evolution is still uncertain, and more observations constraining the sulphur abundance in stellar photospheres are required. | |
dc.description.abstract | Aims. We derive the sulphur abundances in red giant branch (RGB) stars in three Galactic halo globular clusters (GC) that cover a wide metallicity range (-2.3 < [Fe/H] < -1.2): M4 (NGC6121), M22 (NGC6656), and M30 (NGC7099). The halo field stars show a large scatter in the [S/Fe] ratio in this metallicity span, which is inconsistent with canonical chemical evolution models. To date, very few measurements of [S/Fe] exist for stars in GCs, which are good tracers of the chemical enrichment of their environment. However, some light and a elements show star-to-star variations within individual GCs, and it is as yet unclear whether the a element sulphur also varies between GC stars. | |
dc.description.abstract | Methods. We used the infrared spectrograph CRIRES to obtain high-resolution (R similar to 50 000), high signal-to-noise (S/N similar to 200 per px) spectra in the region of the S I multiplet 3 at 1045 nm for 15 GC stars selected from the literature (six stars in M4, six stars in M22, and three stars in M30). Multiplet 3 is better suited for S abundance derivation than the more commonly used lines of multiplet 1 at 920 nm, since its lines are not blended by telluric absorption or other stellar features at low metallicity. | |
dc.description.abstract | Results. We used spectral synthesis to derive the [S/Fe] ratio of the stars assuming local thermodynamic equilibrium (LTE). We find mean [S/Fe](LTE) = 0.58 +/- 0.01 +/- 0.20 dex (statistical and systematic error) for M4, [S/Fe](LTE) = 0.57 +/- 0.01 +/- 0.19 dex for M22, and [S/Fe](LTE) = 0.55 +/- 0.02 +/- 0.16 dex for M30. The negative NLTE corrections are estimated to be in the order of the systematic uncertainties. We do not detect star-to-star variations of the S abundance in any of the observed GCs, with the possible exception of two individual stars, one in M22 and one in M30, which appear to be highly enriched in S. | |
dc.description.abstract | Conclusions. With the tentative exception of two stars with measured high S abundances, we conclude that sulphur behaves like a typical a element in the studied Galactic GCs, showing enhanced abundances with respect to the solar value at metallicities below [Fe/H] -1.0 dex without a considerable spread. | |
dc.description.funder | Deutsche Forschungsgemeinschaft | |
dc.description.funder | FONDATION MERAC | |
dc.fechaingreso.objetodigital | 2024-05-02 | |
dc.format.extent | 9 páginas | |
dc.fuente.origen | WOS | |
dc.identifier.doi | 10.1051/0004-6361/201425058 | |
dc.identifier.eissn | 1432-0746 | |
dc.identifier.issn | 0004-6361 | |
dc.identifier.uri | https://doi.org/10.1051/0004-6361/201425058 | |
dc.identifier.uri | https://repositorio.uc.cl/handle/11534/78282 | |
dc.identifier.wosid | WOS:000353579600018 | |
dc.information.autoruc | Astrofísica;Sbordone L;S/I;243032 | |
dc.language.iso | en | |
dc.nota.acceso | contenido parcial | |
dc.publisher | EDP SCIENCES S A | |
dc.revista | ASTRONOMY & ASTROPHYSICS | |
dc.rights | acceso restringido | |
dc.subject | stars: abundances | |
dc.subject | Galaxy: halo | |
dc.subject | globular clusters: individual: M 4 | |
dc.subject | globular clusters: individual: M 22 | |
dc.subject | globular clusters: individual: M 30 | |
dc.subject | globular clusters: general | |
dc.subject | METAL-POOR STARS | |
dc.subject | ABUNDANCE RATIOS | |
dc.subject | CHEMICAL EVOLUTION | |
dc.subject | ABSORPTION-LINE | |
dc.subject | ZINC ABUNDANCES | |
dc.subject | HALO STARS | |
dc.subject | GALAXIES | |
dc.subject | SI | |
dc.subject | NUCLEOSYNTHESIS | |
dc.subject | SPECTROSCOPY | |
dc.subject.ods | 11 Sustainable Cities and Communities | |
dc.subject.odspa | 11 Ciudades y comunidades sostenibles | |
dc.title | Galactic evolution of sulphur as traced by globular clusters | |
dc.type | artículo | |
dc.volumen | 577 | |
sipa.codpersvinculados | 243032 | |
sipa.index | WOS | |
sipa.index | Scopus | |
sipa.trazabilidad | Carga SIPA;09-01-2024 |
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