École Nationale Supérieure de
Techniques Avancées

Résumé

This report presents the different steps to determine the intrinsic properties of star clusters after their virialisation only from observational data. These properties, such as the Jacobi or the half-mass radius, endure many distortions due to the revolution of the star cluster around the Galactic centre. The tidal effects of the Galactic interactions are especially responsible for this distortion and for the appearance of tidal tails in both sides of the core of the cluster. The purpose of this work is to determine these properties at approximately 70 Myr in the solar neighbourhood, by fitting the cumulative projected profiles – corresponding to observational data – with the real values of these radii. The computations have been done from large N-Body simulations and different analytically known profiles, such as the King’s model or several Polytropes models, have been investigated. After that, the dynamical evolutions of these properties has also been studied.