In this paper, we push forward and exploit an analogy between the morphologies of the X-ray cavities observed in some galaxy clusters, and the optically deficient point-symmetric bubbles occurring in some planetary nebulae (PNe). Point-symmetric PNe are thought to be shaped by stellar binary interactions; namely, the presence of a companion to the PN's progenitor star is required. We suggest that similar point-symmetric structures in the X-ray cavities of galaxy clusters might be associated with the presence of massive binary black holes. A systematic cataloguing of high-resolution images of the diffuse X-ray emission at the core of galaxy clusters might contribute to individuate massive binary black holes.
- (ISM:) planetary nebulae: individual (Hb 5, He 2-47)
- Galaxies: Jets
- Galaxies: clusters: individual (MS 0735.6+7421)
- ISM: planetary nebulae: general
- Stars: AGB and post-AGB
- X-rays: galaxies: clusters