APOD and General Astronomy Discussion Forum
https://asterisk.apod.com/
I would assume that this is the end result of a collision between two galaxies, each with its own supermassive black hole.mark swain wrote:How Did This Happen?
http://woodside.blogs.com/cosmologycuri ... mology.jpg
How did what happen?mark swain wrote:How Did This Happen?
http://www.newscientist.com/article/dn13166The outstanding question really is why we haven't discovered more cases like OJ287 yet.
http://en.wikipedia.org/wiki/OJ287Just how big can black holes get? ... There is no theoretical upper limit
How did these black holes, devour their galaxies in 10 billion years?bystander wrote:How did what happen?
Where did you get this idea? Where does it say these black holes have devoured their galaxies?. As Chris said above, these two black holes probably are in close proximity because of the merger of galaxies. These black holes will soon merge. The larger black hole is probably the survivor of previous mergers.mark swain wrote:How did these black holes, devour their galaxies in 10 billion years?
How do you explain the size, compared to the norm?bystander wrote:Where did you get this idea? Where does it say these black holes have devoured their galaxies?.
18.1 billion solar masses does not come from 2 galaxies.Chris Peterson wrote:I would assume that this is the end result of a collision between two galaxies, each with its own supermassive black hole.mark swain wrote:How Did This Happen?
http://woodside.blogs.com/cosmologycuri ... mology.jpg
What's the norm? As to the size, read the rest of my post above.mark swain wrote:How do you explain the size, compared to the norm?
Since you did not specify your question, I suspect Chris was responding to how one BH came to be orbiting another.mark swain wrote:18.1 billion solar masses does not come from 2 galaxies.
They didn't. OJ 287 is an active galaxy. It isn't an object that has been reduced to a pair of supermassive black holes orbiting each other. It is not that difficult to explain as the simple merger of a pair of galaxies, each with its own supermassive black hole. The contents of the two galaxies haven't gone anywhere, but still exist as the contents of the merged pair. This newer galaxy simply has a pair of supermassive black holes at its center, instead of the usual one.mark swain wrote:How did these black holes, devour their galaxies in 10 billion years?
Black holes don't feed fast. But the mechanism by which the supermassive black holes found at the center of most galaxies initially formed is not yet well understood. It did not necessarily involve their growth by accretion as we now see it. These black holes may have formed quite quickly by different processes altogether. This includes the most massive cases, as well. 18 billion solar masses is still much less than the mass of many galaxies. I see no reason to assume that very massive black holes necessarily formed from multiple galactic mergers, or that they required an extraordinary amount of time to form. There are reasonable theories that explain their existence, even if those theories need more work.18 billion solar masses. + 100 million solar mass = How many galaxies? How long does it take to merge 10 galaxies? But even so, Mr Chris P said him self, Black holes do not feed very fast. A finite time for black hole growth?
