... interaction

Based on data collected at the European Southern Observatory (La Silla, Chile) and at the Cerro Tololo Inter-American Observatory (Cerro Tololo, Chile).

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... Rauw

Chargé de Recherches FNRS (Belgium).

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... Gosset

Chercheur Qualifié FNRS (Belgium).

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...

Visiting Astronomer, CTIO, National Optical Astronomy Observatories (NOAO). NOAO is operated by the Association of Universities for Research in Astronomy, Inc. under contract with the National Science Foundation.

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... IRAF

IRAF is distributed by the National Optical Astronomy Observatories.

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