Observed a possible intermediate black hole in our galactic center

A comma-like molecular cloud near the center of the Milky Way appears to revolve around one of the most sought-after objects in astronomy. Astronomers believe they have observed a possible intermediate black hole in our galactic center. At the center of that strange orbit, in fact, no object is visible, which makes you immediately think of the presence of a black hole. But the cloud data model suggests that this would not just be a normal black hole but one of the rare class of intermediate black holes.  If confirmed, it would be the fifth candidate intermediate black hole observed near the galactic center.

The intermediate black holes

Credits: ESA, Hubble

Also referred to as "missing rings", these hitherto elusive objects could help astronomers understand how supermassive black holes form in the center of galaxies that have colossal dimensions.

Black holes in the Universe tend to be in two distinct mass regimes. There are black holes of stellar mass, up to about 100 times the mass of the Sun. These are black holes that form from the collapse of the nucleus of a massive star at the end of its life, or sometimes from mergers between others of the same type. Then there are the supermassive black holes at the center of galaxies, with masses millions to billions of times that of the Sun.

To date, it is unclear how these colossi are formed, and it is a cosmic puzzle that astronomers would like to solve. And the answer could come just from black holes with intermediate masses. Finding these intermediate mass black holes (called IMBHs) would be proof that black holes evenly cover an entire range of masses and that the intermediate ones are a stage of their growth. But only a few of these medium-weight objects have been identified to date.

One of the problems is that these solitary black holes don’t emit light on their own. They can only be detected by the effect that their immense gravity has on the surrounding environment. And the galactic center is a pretty crowded place, dense with molecular clouds that lead to the stars. Because the region is so dense, it can be difficult to see what’s inside, but a powerful radio telescope can detect its activity. So that’s how the researchers found the cloud, a molecular cloud very close to the galactic center, 27,000 light-years away from us, moving differently than any other material near it.

Its elongated shape is probably the result of the attraction of tidal forces and their modeling has shown that the mass responsible for such interaction is about 100,000 times the mass of the Sun or that of an intermediate black hole. Where it might come from and how it formed are questions that will remain unanswered, but first of all the team of researchers will have to confirm their suspicions. Thanks to the powerful Atacama telescopes in Chile, follow-up observations will be conducted to determine if you can find signs of a black hole, or something else, at the orbital center of the cloud. If it proves to be an intermediate mass black hole, it could have far-reaching implications for our understanding of supermassive black holes.

Science Alert, The Astronomy Journal