Abstract: | How the presence of the hot (kTe ~ 3 - 10 KeV) rarefied gas in the clusters of galaxies (most massive gravitationally bound objects in the Universe) leads to the appearance of "negative sources" in the angular distribution of the Cosmic Microwave Background Radiation and permits to measure the peculiar velocities of these clusters relative to the unique coordinate frame where CMB is isotropic. Planck spacecraft, ground based South Pole and Atacama Cosmology Telescopes discovered recently hundreds of unknown before Clusters of Galaxies at high redshifts detecting these "negative sources". I plan to describe Russian- German Spectrum-X/eRosita space mission able to detect all clusters of galaxies in the observable universe and up to 3 millions of accreting supermassive black holes (Active Galactic Nuclei) during 4 year long X-Ray sky survey. |