Spectroscopic Ages of Elliptical Galaxies - Subaru Observation

Arimoto, Nobuo; Yamada, Yoshihiko; Vazdekis, Alexandre; Peletier, Reynier
Bibliographical reference

Multiwavelength mapping of galaxy formation and evolution, Proceedings of the ESO Workshop held at Venice, Italy, 13-16 October 2003. Edited by A. Renzini and R. Bender. Series Editor: Bruno Leibundgut, ESO, Garching, Germany. ESO astrophysics symposia. Library of Congress Catalog Card No. 2005925391. ISBN 10 3-540-25665-2; ISBN 13 978-540-25565-6; QB857.5.E96 E78 2003. Published by Springer, Berlin, 2005, p.302

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2005
Number of authors
4
IAC number of authors
1
Citations
0
Refereed citations
0
Description
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.