After Sagittarius A*, it would be the second largest black hole in our galaxy. In a study released on September 4th, in Nature Astronomy, researchers at Keio University in Japan reported discovering a gigantic black hole in a molecular cloud 200 light years away from the center of the Milky Way would be about 100,000 times greater than that of the Sun. Not enough to be anything but an intermediate black hole, but a big discovery since their existence had never been proven so far.
This discovery constitutes to date the best proof that we have of the existence of a class of “black holes of average mass”. These could help explain why (and how) supermassive black holes form so quickly. For if it seems enormous for our galaxy, the black hole discovered by astrophysicist Tomoharu Oka and his team is nothing compared to the supermassive bodies that populate the universe, sometimes reaching a mass ten billion times greater than that of the Sun.
Indeed, the manner in which supermassive black holes are formed and how they get so massive still confuse scientists, as the latter can not yet theoretically explain how some of these ancient and gigantic objects seem to have formed when the Universe was still very young. The presence of black holes of intermediate mass could be the key to answer this question. The researchers believe that these could be the seeds leading to their more massive counterparts.
“We believe that some of these black holes are the seeds from which are born supermassive black holes, which are at least a million times more massive,” said astrophysicist Brooke Simmons of the University of California in San Diego to the Guardian after having heard of this new study. This black hole, baptized poetically CO-0.40-0.22, could be all that remains of a dwarf galaxy slowly absorbed by the Milky Way. This suggests that our galaxy would be gluttonous to the point of cannibalizing the less massive galaxies in its vicinity.