A team of Japanese researchers believes it has found evidence of a new type of a black hole hiding in the center of Milky Way galaxy. According to researchers, this black hole is an intermediate-sized black hole (IMBH), about 100,000 times more massive than our Sun, which means it the second biggest known black hole found in Milky Way to date.

This is the first instance of an IMBH being identified

Scientists have known for years that supermassive black holes—weighing as much as ten billion suns—loom in the middle of each galaxy. How such supermassive objects are formed is still a puzzle for researchers and may take several years to be solved completely.

The newly found black hole is however not a supermassive black hole. It weighs just 100,000 times that of our sun and therefore can be put in "intermediate sized" class. Such black holes were earlier believed to exist, but this is the first time that one has been identified.

The team was led by Tomoharu Oka of Keio University

The Japanese team—led by Tomoharu Oka from Keio University—made initial observations using Nobeyama telescope in Japan, and found a big cloud of molecular gas located about 200 light-years away from the heart of the Milky Way. According to researchers, they observed that this gas cloud, called CO–0.40–0.22, was behaving weirdly.

The movement of the gas within this cloud was extremely fast, suggesting that some massive object was located near the cloud and accelerating the gases inside the cloud.

The team hypothesized that this massive object could be an IMBH. The team then used the Atacama Large Millimeter Array in Chile to collect further data. They again detected a similar pattern, but now they also found fainter radio waves originating from the spot where the intermediate-sized black hole (CO–0.40–0.22*) is believed to be sitting.

The researchers say they are not claiming that the source of the radio waves is for sure an IMBH, but their data and computer simulation results do suggest that an IMBH is probably residing in the middle of our galaxy.

The team also believes that CO–0.40–0.22 could be the remains of a dwarf galaxy that was slowly pulled by our galaxy.

These researchers will further study the radio wave emissions and the gas cloud to confirm whether CO–0.40–0.22* is actually what it is being thought to be.

The detailed findings of the study have been published in Nature Astronomy.