Massive Black Holes

These Black holes are the strongest black holes. These black holes are present at the center of every galaxy. The attraction force of this supermassive black hole binds every celestial body. These black holes are the cause that all the bodies(solar system) are in a stable position.

How do these massive black holes form???

When two black holes are close to each other, the gravitational force between these two black holes attract each other . when they are close enough they combine to each other giving a product as huge amount of energy. By combining the size of these black hole does increase with the increase In the field area of their attractive forces thus the combination gives a supermassive black hole which has an enormous energy of attraction. 

location of the massive black hole in milky way galaxy

Our milky way galaxy too has a massive black hole which has held/ bound all of our galaxies together. The location of this black hole corresponds with Sagittarius A^. As milky way galaxy is one of the largest known galaxy , it has a very big/massive black hole. The density of the massive black hole in the milky way galaxy is even less than 997 KG/m^3 which intern is less than the density of water.

 History of research

Donald Lynden-Bell and Martin Rees hypothesized in 1971 that the center of the Milky Way galaxy would contain a supermassive black hole. Sagittarius A* was discovered and named on February 13 and 15, 1974, by astronomers Bruce Balick and Robert Brown using the baseline interferometer of the National Radio Astronomy Observatory. They discovered a radio source that emits synchrotron radiation; it was found to be dense and immobile because of its gravitation. This was, therefore, the first indication that a supermassive black hole exists in the center of the Milky Way.