Dwarf galaxy may have supermassive black hole

Nature : For the first time, images of an ultracompact dwarf galaxy, M60-UCD1, have revealed what may be a supermassive black hole at its center. The discovery was made by Anil Seth of the University of Utah in Salt Lake City and his colleagues, whose findings were published this week in Nature. Based on data from the Hubble Space Telescope and the IR spectrometer on the Gemini North telescope on Hawaii’s Mauna Kea, the astronomers say that the black hole’s mass could be 18% of the mass of all the stars in its galaxy, compared with a typical supermassive black hole, which has only about 0.5% of the mass of its galaxy’s stars. Although no one knows how such supermassive black holes form, the researchers think that M60-UCD1 may have once been much bigger but that a collision with another galaxy resulted in the loss of much of its exterior. Because of the number of dwarf galaxies in the universe, there could be twice as many supermassive black holes as previously estimated.