Joint Astrophysical Colloquium
The enigmatic properties of the ultraluminous X-ray sources
Fabio Pintore (INAF-IASF Palermo)
Thursday 09/02/2023 @ 11:30, Sala IV piano Battiferro - Presenza + remoto
Ultraluminous X-ray sources (ULXs) are extremely bright extragalactic, point-like X-ray sources. It is now thought that the majority of ULXs are in in binary systems and they may host stellar mass black holes or neutron stars accreting at super-Eddington rates. However, it cannot ruled out that the brightest ULXs may host intermediate mass black holes accreting sub-Eddington. Nowadays, the number of confirmed ULXs is of several hundreds and it is further increasing. ULXs show manifold properties in different energy bands and they currently represent a hot topic for the understanding of physical processes related to supercritical accretion onto compact objects. In this talk, I provide a panoramic view of the ULXs multi-wavelength properties from nebulae/bubbles around the sources, the main X-ray spectral and temporal behaviour, and the more recent interpretations of the super-Eddington accretion processes seen in ULXs.