Figures 1 and 2 are only available in electronic form at http://www.edpsciences.org

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Tables 2 and 3 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/440/61

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... IRAF

IRAF is distributed by the National Optical Astronomy Observatories, which are operated by the Association of Universities for Research in Astronomy, Inc. under the cooperative agreement with the National Science Foundation.

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... galaxies

We labeled as ``ellipticals'' those galaxies whose spectra show the absorption CaII H, K features.

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