1020008

The nature of ultraluminous X-ray sources (ULXs) remains unknown. We do not know whether they host stellar- or intermediate-mass black holes nor do we have a clear understanding of the accretion process. Similarly poorly studied is accretion onto supermassive black holes in low-luminosity active galactic nuclei (LLAGN). To address these problems high-sensitivity observations at energies above 10 keV are needed. We propose to add 2+2 Ms of exposure with INTEGRAL in AO9 and AO10 to a 4 Ms exposure to be accumulated in AO7 and AO8 in a unique field where two of the brightest ULXs M82 X-1 and Holmberg IX X-1 and one of the brightest LLAGN M81 are located. We will measure the spectra of these sources in the 3-100 keV energy band and study their spectral variability. A preliminary analysis of ~2.5 Ms of observations provided to us so far confirms the feasibility of achieving our scientific goals. [truncated! Please see actual data for full text]