A rare medium-sized black hole known as NGC 2276-3c could be the "missing link" in the development of exotic bodies astronomers have been seeking for decades. A jet seen emanating from the object also seems to be snuffing out star formation in its neighborhood.
The black hole sits within the galaxy NGC 2276, roughly 100 million light years from Earth.
The European Very Long Baseline Interferometry Network (EVN) and the Chandra X-ray Observatory were used to examine the galaxy, recording objects in radio waves.
Generally, black holes come in two sizes. The smaller of these, between five and 30 times the mass of the sun, are created during supernova explosions of massive stars.
Supermassive black holes, often found at the centers of galaxies, typically have masses millions or billions of times greater than that of our parent star. Although current theory suggests black holes should grow as they age, progressing from stellar-sized objects to the largest specimens, intermediate-sized black holes (Imbhs) are difficult to find, confounding astronomers.
"In paleontology, the discovery of certain fossils can help scientists fill in the evolutionary gaps between different dinosaurs. We do the same thing in astronomy, but we often have to 'dig' up our discoveries in galaxies that are millions of light years away," Mar Mezcua, of the Harvard-Smithsonian Center for Astrophysics, said.
The jet radiating from the black hole stretches 2,000 light years from the black hole, and for half that distance, gases and dust that would normally form new stars has been blown away. This results in a lack of star formation in the region.
"The researchers estimated the mass of NGC 2766-3c using a well-known relationship between how bright the source is in radio and X-rays, and the mass of the black hole. The X-ray and radio brightness were based on observations with Chandra and the EVN. They found that NGC 2276-3c contains about 50,000 times the mass of the sun," Chandra officials reported.
Astronomers are uncertain exactly how NGC 2276-3c formed. One theory states the galaxy in which the black hole sits merged with another group of stars in the distant past. Star formation is seen in other areas of the galaxy, lending support to the theory of an ancient galactic merger. Between five and 15 solar masses of new stars are created each year in the distant galaxy, Chandra data reveals.
The rarity of Imbhs suggest black holes may quickly grow from stellar to supermassive masses. There could also be problems with current theories of black hole formation, researchers speculate.
