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Título:
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Mg and TiO spectral features at the near-IR: spectrophotometric index definitions and empirical calibrations
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Autores:
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Cenarro, A. J. ;
Cardiel López, Nicolás ;
Vazdekis, A. ;
Gorgas García, Francisco Javier
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Tipo de documento:
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texto impreso
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Editorial:
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Wiley, 2009-07-11
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Dimensiones:
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application/pdf
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Nota general:
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info:eu-repo/semantics/openAccess
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Idiomas:
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Palabras clave:
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Estado = Publicado
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Materia = Ciencias: Física: Astrofísica
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Materia = Ciencias: Física: Astronomía
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Materia = Ciencias: Física: Física atmosférica
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Tipo = Artículo
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Resumen:
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Using the near-infrared spectral stellar library of Cenarro et al., the behaviour of the Mg i line at 8807 A and nearby TiO bands is analyzed in terms of the effective temperature, surface gravity and metallicity of the library stars. New spectroscopic indices for both spectral features - namely MgI and sTiO - are defined, and their sensitivities to different signal-to-noise ratios, spectral resolutions, flux calibrations and sky emission-line residuals are characterized. The two new indices exhibit interesting properties. In particular, MgI is a good indicator of the Mg abundance, whereas sTiO is a powerful dwarf-to-giant discriminator for cold spectral types. Empirical fitting polynomials that reproduce the strength of the new indices as a function of the stellar atmospheric parameters are computed, and a fortran routine with the fitting function predictions is made available. A thorough study of several error sources, non-solar [Mg/Fe] ratios and their influence on the fitting function residuals is also presented. From this analysis, an [Mg/Fe] underabundance of similar to -0.04 is derived for the Galactic open cluster M67.
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En línea:
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https://eprints.ucm.es/id/eprint/28028/1/cardiel23libre.pdf
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