Speaker
Description
Ultraluminous X-ray sources (ULXs) are highly energetic extragalactic objects driven by super-Eddington accretion onto stellar-mass compact objects. While the number of ULXs in normal galaxies scales predictably with the star formation rate (SFR), extreme star-forming environments exhibit a significant deficit of ULXs, with populations falling up to a factor of 10 below expected values. To better understand this demographic anomaly, we analysed a sample of ULXs in local Luminous Infrared Galaxies (LIRGs) up to 100 Mpc, resulting in a large catalogue of these sources. Our statistical analysis confirms the observed deficit but leverages the large sample size to place constraints on the properties of the ULXs that successfully form in these dense environments. In this presentation, we evaluate the X-ray luminosity functions (XLFs) of the population, alongside the timing and spectral properties of individual ULXs. We will contrast these findings with normal galaxy populations and propose possible explanations for the suppression of ULXs in extreme starburst environments.