How big can 'ultramassive' black holes get? Scientists may have the answer

[Admin]

Scientists may have discovered a limit to how massive black holes can grow. If they're right, we may have already discovered the largest possible ultramassive black hole!

How big can 'ultramassive' black holes get? Scientists may have the answer : Read more

 

[m4n8tpr8b]

You quote the researcher defining supermassive and ultramassive black holes as more than 10 million resp. 10 billion solar masses, but also that "ultramassive black holes would, on average, be 10,000 times more massive than supermassive black holes." That's a contradiction (10,000 would be the ratio of the heaviest ultramassive black holes and the lightest supermassive ones, not the average ones), but I suspect just a few zeroes were misplaced somewhere.

In fact, to my knowledge, supermassive black holes are defined as more than 100,000 solar masses (a hundredth of what's written in the article), but it certainly cannot be higher than 1 million (our own supermassive black hole at the center of the Milky Way Galaxy, Sagittarius A*, is 4 million). Given that with the 100,000 definition, supermassive black holes cover a much wider range (the largest being 10,000 times the smallest, while for ultramassive ones, it's just 10 times), the 10,000 ratio for average ultramassive and supermassive black holes could hold.

 

[MarkmBha]

Phoenix A may not be just the most massive black hole we have ever detected — it might also be the largest black hole we will ever detect, as it sits right on this limit.

 

[csanyk]

So, OK, scientists believe there's an upper limit to how massive a black hole can become by ingesting interstellar gas. But is that the only way that black holes can grow? I understand that incoming matter can be thrown off by the spin of the black hole, resulting in these jets, and that limits how much of the incoming matter a black hole can take in.

But that's ordinary matter.

What if an ultramassive black hole were to collide with a second ultramassive black hole? Since nothing can escape either black hole, they should not be ripped apart by tidal forces and spill matter that could turn into jet material. That should mean that total ingestion of the black holes as they collide would be the expected result. So if you had a 100 billion solar mass ultra black hole and it collided with another of equal mass, would the resulting UBH weigh in at 200 billion solar masses?

If so then we don't know for sure whether there's an ultimate limit.