0720006

This proposal aims at studying the keV to GeV spectrum and hard X-ray variability of the brightest quasar 3C 273 at obtaining the deepest hard X-ray extragalactic survey and at measuring annihilation and hard X-ray emission from the central region of the Virgo cluster. SPI is the only available instrument for the next decades to be able to detect the presence of anti-matter in the jet of 3C 273. This detection would have profound implications on models explaining jet creation acceleration and collimation as well as the high-energy emission of AGN. The three other instruments of INTEGRAL have enough sensitivity to follow the complex spectral variations of 3C 273 from the optical to the hard X-rays for the first time in coordination with GeV measurements by GLAST. This is a unique opportunity to study the correlations between the various emission components of 3C 273 from the eV to the GeV range and compare them with model predictions. Such observations are possible for the first time during AO6 are easy and have far reaching implications. Key observations will finally be obtained on the hard X-ray emission of M87 probably generated by interaction of its radio bubble and the cooling flow of the Virgo cluster as well as on the expected cluster annihilation emission. Current INTEGRAL observations of the 3C 273 field already provide the deepest hard X-ray extragalactic survey ever made. With the additional exposure we aim at reaching a flux limit of 0.1 mCrab. This will allow to detect sources with typical luminosity up to a redshift of 0.1 probing the evolution of AGN in the hard X-rays over the last billion years. It will also allow to study the implication of absorption for the cosmic X-ray background the absorption/luminosity relationship and the local AGN luminosity function. [truncated! Please see actual data for full text]