Mid-uv narrow-band indices of evolved simple stellar populations
We explore the properties of selected mid-ultraviolet (1900–3200 Å) spectroscopic indices of simple stellar populations. We incorporate the high-resolution UVBLUE stellar spectral library into an evolutionary population synthesis code, based on the most recent Padova isochrones. We analyze the trend...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2009 |
| País: | México |
| Institución: | Instituto Nacional de Astrofísica, Óptica y Electrónica |
| Repositorio: | Repositorio Institucional del INAOE |
| Idioma: | inglés |
| OAI Identifier: | oai:inaoe.repositorioinstitucional.mx:1009/1309 |
| Acceso en línea: | http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1309 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/Inspec/Galaxies: star clusters info:eu-repo/classification/Inspec/Galaxy: stellar content info:eu-repo/classification/Inspec/Globular clusters: general info:eu-repo/classification/Inspec/ultraviolet: stars info:eu-repo/classification/cti/1 info:eu-repo/classification/cti/21 |
| Sumario: | We explore the properties of selected mid-ultraviolet (1900–3200 Å) spectroscopic indices of simple stellar populations. We incorporate the high-resolution UVBLUE stellar spectral library into an evolutionary population synthesis code, based on the most recent Padova isochrones. We analyze the trends of UV indices with respect to age and chemical composition. As a first test against observations, we compare our results with the empirical mid-UV spectral indices of Galactic globular clusters (GGCs), observed with the International Ultraviolet Explorer. We find that synthetic indices exhibit a variety of properties, the main one being the slight age sensitivity of most of them for ages >2 Gyr. However, for high metallicity, two indices, Fe ɪɪ 2332 and Fe ɪɪ 2402, display a remarkably different pattern, with a sharp increase within the first two Gyr and, thereafter, a rapid decline. These indices clearly mark the presence of young (∼1 Gyr) metal-rich (Z ≥ Z⊙) stellar populations. We complement existing UV indices of GGCs with new measurements, and carefully identify a subsample of 10 indices suitable for comparison with theoretical models. The comparison shows a fair agreement and, in particular, the strong trend of the indices with metallicity is well reproduced. We also discuss the main improvements that should be considered in future modeling concerning, among others, the effects of α-enhancement in the spectral energy distributions. |
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