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An inverse method to interpret colour-magnitude diagrams

Jean-Luc Vergely·Joachim Koeppen·Daniel Egret·Olivier Bienayme
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Abstract

An inverse method is developed to determine the star formation history, the age-metallicity relation, and the IMF slope from a colour-magnitude diagram. The method is applied to the Hipparcos HR diagram. We found that the thin disk of our Galaxy shows a peak of stellar formation 1.6 Gyr ago. The stars close to the Sun have a solar metallicity and a mean IMF index equal to 3.2. However, the model and the evolutionary tracks do not correctly reproduce the horizontal giant branch.

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Jean-Luc Vergely, Joachim Koeppen, Daniel Egret, Olivier Bienayme. 2002-03-06. An inverse method to interpret colour-magnitude diagrams. https://doi.org/10.1051/0004-6361%3A20020334

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