ULX population in nearby galaxies from XMM

From our list of approximately 100 point sources, we attempt to determine if there is a low-state counterpart to the ultraluminous X-ray (ULX) population, searching for a soft-hard state dichotomy similar to that known for Galactic X-ray binaries and testing the specific predictions of the intermediate-mass black hole (IMBH) hypothesis.

To this end, we searched for low-state objects, which we defined as objects within our sample that had a spectrum well fitted by a simple absorbed power law, and high-state objects, which we defined as objects better fitted by a combined blackbody and a power law.