'Seeds' of Supermassive Black Holes Discovered 37
astroengine writes "The very existence of intermediate black holes (IBMHs) is in dispute, but a group of astronomers of Keio University, Japan, have found the potential locations of three IMBH candidates inside previously unknown star clusters near the center of the Milky Way. Using the 10-meter Atacama Submillimeter Telescope Experiment in the Atacama Desert, Chile, and the 45-meter Nobeyama Radio Observatory in Japan, they hunted for the emissions from molecular gases associated with supernovae in star clusters — what they discovered could help evolve our view on how supermassive black holes form."
Re:Really? (Score:5, Insightful)
The reason astronomers seem to dispute the potential for the existence of these intermediate mass black holes is that no one has yet shown convincing evidence that they exist, nor do they have any convincing theories on how they could be formed. No star is massive enough to have collapsed into the alleged IMBH GCIRS 13E [wikipedia.org], which is supposed to be 1300 solar masses. For several smaller stellar black holes to coalesce into something like GCIRS 13E, that seems far less likely. Away from galactic cores where everything is very close together, stellar collisions are extremely rare. Collisions between black holes considerably more so. Contrary to popular perception black holes are not the all-sucking vacuum cleaners of the universe. Their gravity is not so different from the gravity of any other object, except beyond the event horizon. A stellar black hole five times the mass of our sun would have no more ability to attract things to itself with gravity than a star of five solar masses. So while black holes could collide, in interstellar space they don't do so very frequently, as much of interstellar space is empty, and as such, a few hundred of them coming together to form an IMBH of a thousand or so solar masses is extremely unlikely to say the least. In galactic cores on the other hand things are so close together that accretion of stuff into a black hole there would tend to continue until there's a supermassive black hole, not stopping at the thousand or so solar masses that IMBHs are hypothesized to be. The only other explanation for the formation of IMBHs is that they are primordial black holes created a fraction of a second into the birth of the universe, but this is even more shaky to say the least. Regardless of the explanation, the fact is observational evidence for IMBHs is disputed, and is nowhere near as conclusive as the evidence for stellar and supermassive black holes is. Granted, they could exist in principle, but if observational evidence is flimsy and the conditions necessary for creating one so unlikely then one might be justified in doubting their existence.