Speaker
Description
The M82 galaxy harbors two of the most interesting ultraluminous X-ray sources (ULXs) -- off nuclear point sources radiating above the Eddington limit for a typical stellar remnant black hole.
Some ULXs might be sub-Eddington intermediate-mass black holes, but the bulk of this class is now widely believed to be powered by super-Eddington accretion onto compact objects.
In a handful of cases, this was proven by the detection of pulsations, which unequivocably identify the accretor as a neutron star. In a few other cases, the luminosity is so high that the leading interpretation remains sub-Eddington X-ray binaries powered by IMBH.
M82 contains the first discovered pulsating ULX and one of the leading IMBH candidates.
In this talk, I will review the information these remarkable sources have given us on extreme accretion over the years, and present some recent results exploiting time domain information to investigate these sources.