Can Two Black Holes Really Collide, Even If They Were Once Stars?

[wolram]

For this to happen there must have been two stars that went super nova in close
proximity, if so i find hard to think that a star would survive a very close companion going nova, so how do the two black holes get close enough to collide?

 

[mathman]

Any two objects flying around in space could pass near each other and mutual gravity could alter their paths enough for them to collide.

 

[wolram]

Any two objects flying around in space could pass near each other and mutual gravity could alter their paths enough for them to collide.

Thats a lot of could s how many black holes are there floating around.

 

[staf9]

Thats a lot of could s how many black holes are there floating around.

There's quite a few, centers of certain galaxies included.

I'm sure this phenomenon that you talk about originally has happened at some point in the history of our universe, given the sheer number of stars that we know of that have died and black holes that we know of (not to mention the countless ones we don't know of), and my guess on this matter (and it is a guess, since we have no idea what happens to something when it hits the singularity of a black hole) is that the masses of the black holes combine to create a bigger one.

 

[wolram]

We are supposed to be living in an expanding universe so i guess the only chance for black hole merger is within local groups of galaxies, has a merged galaxy been observed that exhibit the behavior of having two massive black holes in it.

 

[wolram]

Existing Ligo should be able to detect 10 mergers per year?

http://arxiv.org/PS_cache/astro-ph/pdf/0701/0701887v2.pdf

Well it does not, so either i have read this wrong or there is some thing else amiss.

 

[Contrapositive]

For this to happen there must have been two stars that went super nova in close
proximity, if so i find hard to think that a star would survive a very close companion going nova, so how do the two black holes get close enough to collide?

Why not? I think another star, especially one that is big enough to make a black hole would have enough mass to hold itself together near a supernova.

 

[jimgraber]

Oj287

We are supposed to be living in an expanding universe so i guess the only chance for black hole merger is within local groups of galaxies, has a merged galaxy been observed that exhibit the behavior of having two massive black holes in it.

Yes, at least one such is known. It's called OJ287.
There was more info released at the recent AAS meeting.
Here's a BBC link:

http://news.bbc.co.uk/1/hi/sci/tech/7181877.stm

Jim Graber

 

[wolram]

The BH is equal to 18 billion suns? has this BH been stoked since time began?