Accretion -

in astronomy, this term shall be distributed matter fall onto the surface of a celestial body by the action o f gravity. Phenomenon may be accompanied by the secretion of larg e amounts of energy in the form of electromagnetic radiation when matter falling ordain some lost gravitational potential energy. Particularly spectacular is the accretion of compact objects - white dwarfs, neutron stars or black holes. It is believed that the mechanism feed Active Galactic Nuclei is the accretion of matter at the supermassive black hole.