0820030

The nature of ultraluminous X-ray sources (ULXs) remains controversial. 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 the accretion onto supermassive black holes in low-luminosity active galactic nuclei (LLAGN). To address these problems sensitive observations at energies above 10 keV are needed. We propose to observe with INTEGRAL for a total exposure of 4 Msec (2 Msec in AO7 + 2 Msec in AO8) a unique sky region 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 from 3 keV up to 50--100 keV and possibly study their spectral variability. At the time of this writing ~1.5 out of the 2 Msec of observations granted in AO7 have been provided to us. A preliminary analysis of these data confirms the feasibility of achieving our scientific goals upon completion of the entire observational campaign. [truncated! Please see actual data for full text]