087094

The galaxy M82 harbors two notable ultraluminous X-ray sources openParULXclosePardoublePoint M82 X-2 comma the archetipal pulsating ultraluminous X-ray source openParPULXclosePar comma and M82 X-1 comma a IMBH candidate. The extreme luminosity of ULXs comma and the observation of strong winds from these sources comma suggests that these sources are undergoing strongly super-Eddington accretion. The supply of matter that powers these accreting systems is likely to come from Roche Lobe overflow from a more massive companion star comma and should produce changes of orbital period observable in time scales of virgulyears. This program aims at detecting this orbital period derivative through pulsar timing in M82 X-2 comma and study in detail the quasi-periodic oscillations from both ULXs.