|
0 members (),
347
guests, and
0
robots. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
|
Joined: Feb 2007
Posts: 1,840
Megastar
|
OP
Megastar
Joined: Feb 2007
Posts: 1,840 |
Observations have long shown that supermassive black holes exist in the cores of active galaxies, the early stages of which are said to be quasars. Computer simulations predicted that, when galaxies collide, a black hole can be ejected from a galactic core, and thus exist separately in intergalactic space thereafter. Recent observations have provided strong evidence that this does, in fact, happen. http://www.universetoday.com/2008/04/29/...er-observation/
|
|
|
|
|
Joined: Oct 2004
Posts: 1,696
Megastar
|
|
Megastar
Joined: Oct 2004
Posts: 1,696 |
<........Computer simulations predicted that, when galaxies collide, a black hole can be ejected from a galactic core, and thus exist separately in intergalactic space thereafter. Recent observations have provided strong evidence that this does, in fact, happen. http://www.universetoday.com/2008/04/29/...er-observation/ That is a very interesting find, redewenur. It makes one wonder how many other Black Holes are 'wizzing' around our Galaxy, on their own? I say wizzing because this ones speed not far short of 7 million miles per hour. I suppose it has become a type of vacuum cleaner able to sweep up any material in its path and grow bigger? That itself could raise some interesting questions. I wonder what the effect might be upon the 'kicked out galaxy' now it has vastly increased in size? What effect upon the Stars on its new outer periphery, as they are under less gravity? By how much would this enlarged Galaxy compact down? Will its original Black Hole become more active?. And just how many more 'runaway' Black holes might there be, flying about in Galactic space? Or even static invisible ones?
.  . "You will never find a real Human being - Even in a mirror." ....Mike Kremer.
|
|
|
|
|
Joined: Sep 2006
Posts: 194
Senior Member
|
|
Senior Member
Joined: Sep 2006
Posts: 194 |
The problem I have with this scenario is that supposedly nothing can escape a black hole and if two galaxies were to collide I would think it would go doubly sure that neither of those Black Holes woud allow the other to escape to theultimate destruction of the smaller hole.
|
|
|
|
|
Joined: Feb 2007
Posts: 1,840
Megastar
|
|
OP
Megastar
Joined: Feb 2007
Posts: 1,840 |
The problem I have with this scenario is that supposedly nothing can escape a black hole and if two galaxies were to collide I would think it would go doubly sure that neither of those Black Holes woud allow the other to escape to theultimate destruction of the smaller hole. Yes, I agree, it's surprising. From the contradictory news items available at present, it's not clear exactly what does happen This from the previous link: Models predict that as two fast-rotating black holes begin to merge, gravitational radiation is emitted through the colliding galaxies. As the waves are emitted mainly in one direction, the black holes are thought to recoil - much like the force that accompanies firing a rifle. The situation can also be thought of as two spinning tops, getting closer and closer until they meet. Due to their high angular momentum, the tops experience a "kick", very quickly ejecting the tops in the opposite directions. This is essentially what two supermassive black holes are thought to do, and now this recoil has been observed. But the following from http://news.xinhuanet.com/english/2008-04/30/content_8083758.htmEventually, the black holes would fuse, and "in the final coalescence, or merger, of these two black holes, a giant burst of gravitational waves is emitted," she said. "Since these waves are generally emitted in one preferred direction, the black hole is then kicked in the other direction."
|
|
|
|
|
Joined: Sep 2006
Posts: 194
Senior Member
|
|
Senior Member
Joined: Sep 2006
Posts: 194 |
The problem I have with this scenario is that supposedly nothing can escape a black hole and if two galaxies were to collide I would think it would go doubly sure that neither of those Black Holes woud allow the other to escape to theultimate destruction of the smaller hole. Yes, I agree, it's surprising. From the contradictory news items available at present, it's not clear exactly what does happen This from the previous link: Models predict that as two fast-rotating black holes begin to merge, gravitational radiation is emitted through the colliding galaxies. As the waves are emitted mainly in one direction, the black holes are thought to recoil - much like the force that accompanies firing a rifle. The situation can also be thought of as two spinning tops, getting closer and closer until they meet. Due to their high angular momentum, the tops experience a "kick", very quickly ejecting the tops in the opposite directions. This is essentially what two supermassive black holes are thought to do, and now this recoil has been observed. But the following from http://news.xinhuanet.com/english/2008-04/30/content_8083758.htmEventually, the black holes would fuse, and "in the final coalescence, or merger, of these two black holes, a giant burst of gravitational waves is emitted," she said. "Since these waves are generally emitted in one preferred direction, the black hole is then kicked in the other direction." Ok, I read the article in the link but my question is this, how can a black hole be seen leaving a galaxy when the only way to see a black hole is by monitoring the effects it has on nearby matter?
|
|
|
|
|
Joined: Feb 2007
Posts: 1,840
Megastar
|
|
OP
Megastar
Joined: Feb 2007
Posts: 1,840 |
Rallem: "...how can a black hole be seen leaving a galaxy when the only way to see a black hole is by monitoring the effects it has on nearby matter?"
No one, of course, has ever seen, nor will they ever see, a black hole. It's matter of deduction, as with all other observations concerning black holes.
"Time is what prevents everything from happening at once" - John Wheeler
|
|
|
|
|
Joined: Sep 2006
Posts: 194
Senior Member
|
|
Senior Member
Joined: Sep 2006
Posts: 194 |
But in the article you posted it clearly said that a black hole had been seen leaving its parent galaxy. Usually scientific articles are very specific on their terminology and it is the science amateur like me who fouls up the understanding.
|
|
|
|
|
Joined: Feb 2007
Posts: 1,840
Megastar
|
|
OP
Megastar
Joined: Feb 2007
Posts: 1,840 |
Yes, "detected" would have been a better word. But, then, although black holes have been shown to exist with a high degree of certainty, the best confirmation would be the detection of their gravitational waves. The problem is, the situation with gravitational waves is similar to that of black holes - while they've been indirectly shown to exist, they haven't yet been directly detected. This is interesting. A simulation of colliding galaxies (alas, minus ejection of black hole) http://burro.cwru.edu/SSAnims/SFLD.mpg (8.2 Mb)
|
|
|
|
|
