Astronomers have discovered a black hole lurking in the galaxy. The intermediate-mass black hole, one of over 100 million quiet black holes believed to be lurking in the Milky Way, was detected from its effects on an interstellar gas cloud.
Black Holes
Black holes have such a strong gravity it can suck in everything, including light. Because these objects do not emit light, astronomers only infer their existence based on the effects of their gravity on other objects.
The discovery of this black hole may pave way for a new method of searching for other hidden blacks and provide a better understanding of how black holes grow and evolve.
New Method To Find Other Black Holes
Shunya Takekawa, from the National Astronomical Observatory of Japan, and colleagues used the Atacama Large Millimeter/submillimeter Array to conduct a further investigation after observing the gas cloud HCN-0.009-0.044 moving near the center of the galaxy 25,000 light years away.
By using ALMA to perform high-resolution observations of the cloud, the researchers discovered it was swirling around an invisible massive object.
"Detailed kinematic analyses revealed that an enormous mass, 30,000 times that of the Sun, was concentrated in a region much smaller than our Solar System," Takekawa said.
The researchers think this was the smoking gun of an intermediate-mass black hole since there was no object observed at the location. Intermediate-mass black holes weigh hundreds to thousands of times the solar mass.
In their study published in The Astrophysical Journal Letters, Takekawa and colleagues said that by analyzing other anomalous clouds, they hope to detect other quiet black holes.
Proof Of Merger Model Of Black Hole Growth
Black holes range in mass. Some are only about five times as massive as the sun, while some are millions of times more massive than the sun. Astronomers think that small black holes merge and gradually grow into big ones.
Study researcher Tomoharu Oka, from Keio University, said the newly detected intermediate-mass black hole being found only 20 light years away from the supermassive black hole at the center of the galaxy has significant implications.
"In the future, it will fall into the supermassive black hole, much like gas is currently falling into it. This supports the merger model of black hole growth."
