... Behemoth black hole found in an unlikely place . Gravitational wave search provides insights into galaxy evolution and mergers . ... galaxies . ... Astronomers find source of most powerful cosmic rays . ... The supermassive black hole at the center of our galaxy is likely to accelerate cosmic ray particles to energies 100 times larger than those achieved at the largest terrestrial particle accelerator, the Large Hadron Collider at European Organization for Nuclear Research (CERN) in Switzerland. ...