Based on VLT observations collected at the European Southern Observatory, Chile, Swiss GTO program 072.B-0237.

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Tables 4 and 5 are only available in electronic form at http://www.aanda.org

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... IRAF

IRAF is the Image Reduction and Analysis Facility distributed by the National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under cooperative agreement with the National Science Foundation (NSF).

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