Dwarf galaxies could help reveal supermassive black holes' origin

Astronomers have discovered more than 100 small, dwarf galaxies with characteristics indicating that they harbor massive black holes feeding on surrounding gas; this could help resolve the question as to how black holes originated and grew in the early universe.

Amy Reines, of the National Radio Astronomy Observatory (NRAO), said that the little galaxies hold the clues to the origin of the first ‘seeds’ of supermassive black holes in the early universe.

Reines, along with Jenny Greene of Princeton University and Marla Geha of Yale University, analyzed data from the Sloan Digital Sky Survey and found more than 100 dwarf galaxies whose patterns of light emission indicated the presence of massive black holes and their feeding process.

Geha said that the galaxies are comparable in size to the Magellanic Clouds, dwarf satellite galaxies of the Milky Way, asserting that previously, such galaxies were thought to be too small to have such massive black holes.

In the nearby universe, astronomers have found a direct relationship between the mass of a galaxy’s central black hole and a “bulge” in its center. This indicates that the black holes and the bulges may have affected each others’ growth.