0920010

This proposal aims at obtaining the deepest hard X-ray extragalactic survey at studying the keV to GeV spectrum and hard X-ray variability of the brightest quasar 3C 273 and at measuring annihilation and hard X-ray emission from the central region of the Virgo cluster. 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. 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 in coordination with GeV measurements by Fermi. 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 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. [truncated! Please see actual data for full text]