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Your search keyword '"Vazdekis, A."' showing total 25 results
Start Over Author "Vazdekis, A." Publication Type Books
25 results on '"Vazdekis, A."'

22. Stellar Populations in Compact Group Elliptical Galaxies.

Author

Leibundgut, Bruno, Saviane, Ivo, Ivanov, Valentin D., Borissova, Jordanka, de la Rosa, I.G., de Carvalho, R.R., Vazdekis, A., and Barbuy, B.

Abstract

Elliptical galaxies in Hickson Compact Groups (HCGs) are compared with their counterparts in the field. The stellar populations have been studied with two alternative models and reduction strategies to ensure the robustness of the results. Furthermore, great care has been taken to correct for emission contamination by Balmer lines, used to determine the ages of the galaxies. We find that, compared to the field, galaxies in HCGs are systematically older and more metal-poor, in agreement with previous works. For the first time, we show that the less massive galaxies in HCGs show an enhanced [Mg/Fe] abundance ratio compared to the field. This enhancement is interpreted as a relic of an event which truncated the galactic star formation, when the abundance ratio was still high. Recent hydrodynamical simulations predict such truncation after a galaxy merger, believed to be a common interaction in HCG environments. [ABSTRACT FROM AUTHOR]

Published
2007
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23. Spectroscopic Ages of Elliptical Galaxies - Subaru Observation.

Author

Renzini, Alvio, Bender, Ralf, Arimoto, Nobuo, Yamada, Yoshihiko, Vazdekis, Alexandre, and Peletier, Reynier

Abstract

Breaking age/metallicity degeneracy ([19], [1]) is crucial for understanding stellar populations in elliptical galaxies. Spectroscopic properties, such as line strength, can partially break age/metallicity degeneracy. Reference [19] found that Hβ index, defined in [4] (Lick indices), is relatively sensitive to luminosity-weighted age of galaxies. But emission line makes Hβ shallower, therefore correction of emission line effect is necessary. Hγ and Hδ indices, such as HγA, HδA, HγF and HδF, which are less affected by emission than Hβ, are defined in [8] and [20]. However, those indices are still affected by age/metallicity degeneracy, since they are measured on low resolution spectra (9-11 Å). Reference [8] defined HγHR to find it strongly sensitive to age. But HγHR is much affected by velocity dispersion (σ) of galaxies, since the bandpasses of feature and pseudocontinua are very narrow. [ABSTRACT FROM AUTHOR]

Published
2005
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24. The Relation Between Stellar Populations and Light Profiles in Early-Type Galaxies.

Author

Renzini, Alvio, Bender, Ralf, Vazdekis, Alexandre, Trujillo, Ignacio, and Yamada, Yoshihiko

Abstract

Early-type (E/SO) galaxies follow tight relations such as the Fundamental Plane, the Color-Magnitude Relation or the Mg2-σ relation (Bender et al. 1992). However little is known about the relation between their morphological shapes and stellar populations (Conselice 2003), most likely because these two fields rely on methods that have grown up separately. Here we explore possible correlations between the Sérsic index n, and relevant stellar population parameters. [ABSTRACT FROM AUTHOR]

Published
2005
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