Galaxy clusters seen in X-rays: from the most relaxed to the most perturbed - Durret, F; Lima Neto, Gastão Cesar Bierrenbach; Adami, C; Bagchi, J; Covone, G; Forman, W; Kneib, J.-P; Slezak, E; Soucail, G (SF2A-2005: Semaine de l'Astrophysique Francaise, 2005)