A team of scientists led by the astrophysicist Tomoharu Oka from Keio University (Japan) has detected a gigantic black hole of about 100,000 times the mass of the Sun near the heart of our galaxy together with the already known Sgr A. This object would be a new Intermediate-mass black hole (IMBH) candidate.
The black hole, which is hidden in a huge cloud of molecular gas, is the best evidence for a known “intermediate mass ” type of black hole, the existence of which could explain how supermassive black holes grow so huge. Because, although this black hole is itself quite large, the truth is that its mass pales in comparison to the supermassive black holes found in the center of galaxies, with up to 10 billion solar masses.
How these black holes get so massive is something that science cannot yet explain, but there are some hypotheses.
Intermediate mass black holes
One of them deals with the presence of what we call intermediate mass black holes, which perhaps act as seeds for their more massive counterparts. Perhaps this is the case in this new black hole located behind a gas cloud called CO-0.40-0.22, just 200 light years from the center of the Milky Way.
The unusual gas motions detected within CO-0.40-0.22 suggested a year ago that a massive force was accelerating matter within the cloud , which the researchers considered to be our best candidate for an intermediate-mass black hole. The data was backed up with new measurements taken by the Atacama Observatory in Chile.
Once again, the researchers detected a velocity distribution within a group of gas in the cloud, but this time they found something else: a spectrum of radio waves, similar to the readings produced by Sagittarius A, but about 500 times dimmer. .
Although it cannot be confirmed tactically that the origin of this source is an intermediate mass black hole, the latest results offer our best and least ambiguous evidence for this type of phenomenon to date.
Experts believe that this gas cloud could be the remnant of a dwarf galaxy that was slowly pulled into the Milky Way, suggesting that larger galaxies – and the supermassive black holes they contain – grow cannibalizing their smaller neighbors.
Researchers will continue to study the gas cloud and its radio wave emissions in order to confirm once and for all whether what hides this gas cloud is the intermediate mass black hole we suspect it to be.
Until then, we will have to wait and marvel at the mystery of this epic missing link in the cosmos.
Reference: Tomoharu Oka, Shiho Tsujimoto, Yuhei Iwata, Mariko Nomura & Shunya Takekawa Millimeter-wave emission from an intermediate-mass black hole candidate in the Milky Way. 2017. Nature Astronomy. doi: 10.1038 / s41550-017-0224-z
Image credit: Keio University (Japan).
