What Happens When Supermassive Black Holes Collide?
Written by Fraser Cain
As galaxies merge together, you might be wondering what happens with the supermassive black holes that lurk at their centres. Just imagine the forces unleashed as two black holes with hundreds of millions of times the mass of the Sun come together. The answer will surprise you. Fortunately, it's an event that we should be able to detect from here on Earth, if we know what we're looking for.
Most, if not all, galaxies in the Universe seem to contain supermassive black holes. Some of the biggest can contain hundreds of millions, or even billions of times the mass of our own Sun. And the environments around them can only be called "extreme". Researchers think that many could be spinning at the maximum rates predicted by Einstein's theories of relativity - a significant fraction of the speed of light.
As two galaxies merge, their supermassive black holes have to eventually interact. Either through a direct collision, or by spiraling inward until they eventually merge as well.
And that's when things get interesting.
According to simulations made by G.A. Shields from the University of Texas, Austin, and E.W. Bonning, from Yale University, the result is often a powerful recoil. Instead of coming together nicely, the forces are so extreme that one black holes is kicked away at a tremendous velocity.
The maximum kick happens with the two black holes are spinning in opposite directions, but they're on the same orbital plane - imagine two spinning tops coming together. In a fraction of a second, one black hole is given enough of a kick to send it right out of the newly merged galaxy, never to return.
As one black hole is given a kick, the other receives a tremendous amount of energy, injected into the disk of gas and dust surrounding it. The accretion disk will blaze with a soft X-ray flare that should last thousands of years.
So even though mergers between supermassive black holes are extremely rare events, the afterglow lasts long enough that we should be able to detect a large number out there in space right now. The researchers estimate that there could be as many as 100 of these recent recoil events happening within 5 billion light-years of the Earth.
Their recently updated journal article, entitled Powerful Flares from Recoiling Black Holes in Quasars will be published in an upcoming issue of the Astrophysics Journal.
Original Source: Arxiv
Filed under: Astronomy, Black Holes
March 3rd, 2008 at 9:23 pm
Astrofriend is probably correct concerning emissions. Good thinking!
March 4th, 2008 at 5:55 am
Astrofriend makes sense for what we know, which may not be much. "Assuming black hole theory is correct, nothing can escape a black hole". Yes for what theory says but that doesn't quite hold up when you start applying it to the "Big Bang". We are all still in nursery school when it comes to what is really going on.
March 7th, 2008 at 7:13 am
Not sure if anyone is still following this but I was asked to elaborate.
Mr. Arp's research showed that QSO's had a remarkable, and statistically amazing, tendancy to be located in the area near "peculiar" galaxies, which we are aware today are often two or more galaxies in the process of collision and integration. QSO's with high red-shifts are assumed to be tremedously distant objects, and thus could not be physically associated with the nearby galaxies that Apr's research showed them to be located near on photographic plates that he studied, at least that is the predominent thinking. Since the QSO red shift, and consequent calculation of the Hubble constant, all fit neatly into the idea of universal expansion, the great majority of Arps contemporaries (and still today) did not want to have the universal expansion bubble burst by Arps "silly" ideas Arp's idea was that, given a nearly impossible to be cooincedence statistical correlation of QSO's and peculiar galaxies in terms of location, and in in terms of what appear to be visible streams of stars connecting them, then at least some QSO's were NOT at tremendous distances at all and that there was some other possible explanation for the red-shifts. Arp has been roundly labeled a lunatic by modern physicists, and his ideas summarily dismissed. As for the spectral analysis of QSO's "the features of their emission spectrums (both broad and detailed) etc. etc. are not stellar in any way shape or form.." Correct me here if I am wrong but if one explanation for Arp's QSO's is that they may be highly accelerated ejected black holes, I would think their spectrum might be expected to by rather non-stellar appearing would it not?
March 11th, 2008 at 10:24 am
well i have an idea….mabey if two supermassive black holes were to at least try to collide then mabey they would because if one is spinning one way and the other is spinnig the other way then mabey they would but no one can say they wouldnt because no one really knows !!!!!!!
March 25th, 2008 at 2:52 pm
hehehehe anyone up for some black hole spinning top fights?
March 27th, 2008 at 3:02 am
both massive black hole will dissepired… acording 2 pysic law.. the volcano and dinemite… just the matter…
March 27th, 2008 at 2:30 pm
A merger of 2 supermasive black holes at the center of a galaxy would increase gravitational field of the new black hole and have a significant impact on the rest of the galaxy.
April 8th, 2008 at 4:41 am
So if this happens would there be a bunch of black holes out there just floating around in space capturing anything between the galaxies that gets near it?? We would never see it coming!
July 9th, 2008 at 11:11 pm
My thoughts ,if they say you went into the outer portion of a black hole you would be accelerated forward in time and if you were able to come back out you would see that you have gone into the future without aging as much as your surroundings . That means for an observer that watched you go into the future you just popped out of existence because you left to go into the future . So thinking on that note if two black holes merge there should be only the slightest ghost of the happening the intruding black hole went into the future by going into a black hole ! if its gone there then so has most of its gravitational forces . Now look at this from a distance and see that there were two high gravity objects thats two forces now join them and one force disappears ! This will produce a missing gravity wave if all theory is correct. Or if the thing should fly apart and still make two again there should be some very small black holes produced between them that should have such a small mass as to not be able to maintain the black hole effect thus bringing matter back into normal existence (an EXPLOSION OF NEW MATTER BETWEEN two black holes going in opposite directions ) . And possibly the mini black holes that can still exist as black holes ,could these be small enough to allow light to be in orbit around them and showing flashes whenever an object gets sucked into them while hitting this orbiting light shell ? Is there a shell of light orbiting at a precise distance from all black holes that is similar to a laser in that it gets stronger and actually aligns itself to the point of lasing emissions sporadically or when an object hits its orbit disturbing its orbit ? I think we really don't have an understanding of what black holes are yet ! We need to watch these constantly to see what is happening . Are black holes really ghosts of matter going into the future and we are only seeing the glimpse of them passing by ? Including their gravity . Wouldn't this produce a very different kind of gravity than we expect ? Where there is giant explosions of matter like in a new star is there two black holes flying away from it making trails through the merging galaxies as they add to their mass ? What if the two black holes met so violently that they went into an expansion that ended their life as black holes then all of the matter would suddenly appear as in a big bang ?
I do have some great dreams !
July 19th, 2008 at 9:43 am
[...] gravitational waves, shunting the smaller black hole in the opposite direction. The process can be envisioned as two spinning tops slowly approaching each other; when they touch, the huge angular momentum blasts the tops away from [...]
August 3rd, 2008 at 7:14 am
If two supermassive galactic black holes "collide" such that one is flung away, do the contents of the black holes get close enough that their event horizons merge or make contact?
August 3rd, 2008 at 3:44 pm
It is interesting that David Gronczniak and I independently arrived at one possible product of two massive "high spin" black holes colliding - that being black holes formed from initial masses much smaller than could be created through the normal stellar processes. With such massive forces at play, perhaps a small object, say the mass of earth, could be "compressed" right down to a singularity. What size would the accretion disk be? The size of a marble? Smaller? What if one of these flung itself into our solar system - what effects would it have? Would it orbit? What if it collided with a planet like earth? How long would it take for it to absorb another planet? What if it was flung out at such a velocity that it screamed through our solar system at a high fraction of the speed of light? Would it pass through a planet like earth and keep on going? If so, how much matter would it suck in as it passed through our planet? What effects would it have on our planet as it passed through? What if this neo-black hole was created from a mass as small as 1/1000 earths mass - how small would its accretion disk be? Can this be calculated? The size of a bacterium? A molecule? What if that hit the earth at a high fraction of the speed of light? Any ideas?
September 16th, 2008 at 10:54 pm
Thinking about Bob Kapli's idea , neutrinos sort of act like mini black holes and they seem to pass right through planets ! If they were really little black holes then any thing they would hit would instantly be absorbed . This absorption process would tend to actually speed up the total particles mass , so here it is the particle that exists here and now that on a sub atomic level gets absorbed into an on coming black hole both attract each other and accelerate towards this combining action then upon joining the hit particle gets placed into the future and being no longer here tends not to slow down the original mini black hole it sort of explains how a black hole is not impeded by a planet in its way . However some deflection in its original path would probably occur as the absorb process would very likely be off center thus the in and out path might not (match or line up )make sense in the detectors they use for finding neutrinos . They look for neutrinos with large tanks of a chemical as the detector ,in the bottom of mine shafts deep in the earth as no other particle (except for a black hole) can penetrate that far. If they could examine the entry and exit hole of the detector tank they might find out something new ! This is becoming possible with our newest technology . The new particle accelerator in Geneva might get these results . I think that a black hole traveling at a very high speed near the speed of light would be really strange ,this is matter that is already traveling into the future even if standing still but add the speed and get an even faster launch into the future ,nullifying the effects of becoming more massive as the approach of light speed is almost reached. This is really hard to imagine ,what would it appear to be ?
December 22nd, 2008 at 6:12 pm
when two black holes of near equal size collide a big bang will happen .If one is larger than the other , the smaller will be absorbed. therefore many "big bang" might be possible. This I have thought for many years.
January 5th, 2009 at 10:23 pm
A little thing about black holes is how there can be any differences in their sizes? This is what should be happening if the science is correct , mass reaches a concentration of sufficient amounts to cause the collapse of the spacing between atoms and shrinks in physical size it takes up visually . Now this still has all its mass but in a smaller more concentrated package . Now its coined as being a black hole as its gravity is such that light cannot escape and all the definitions of a black hole are officially in play. I don't believe this to be true because of the idea that going into a close orbit of a black hole would bring you into the future as you are feeling the effects of its high gravity. If this were true then the stuff in the black hole has already gone into the future along with its gravity !
So the black hole is now almost a ghost of itself with less apparent gravity as most of or all of its mass has gone into or in the process of going into the future at an accelerated rate ! So if this is whats happening then why should the physical gravity or appearance of a black hole be able to be changed by the addition of more mass ? Any more mass merely gets transported into the future upon entering its core . It could not just be simply be added to its mass as its mass is traveling into the future already !
So the idea for me is there is theoretically only one actual size for all black holes to appear to us in our present way that time occurs for us in this universe or dimension . Now that they are saying that there is different sizes for black holes actually proves they don't really have a good definition at all of what they are ! Possibly i think these are really like giant capacitors or rechargeable batteries that in our view look like black holes but are really not what they seem to be they have no emitting radiations of anything but gravity but might be the entrances to other existences and be emitting their energies there. This might account for different apparent sizes for black holes they are possibly the entrance hole of different sizes to the other dimensions , and the flow between is at different rates . This would tend to cause sort of a traffic jam and make them appear larger and have more gravity . I think there are black holes of very small size and having very localized effects that are extremely fast accelerators of matter into the future .
It would look like an implosion point where things just disappear and actually not look like an actual physical object of any type or size. As soon as matter enters its area it is absorbed and the noticed effect would be the ripple in the matter that surrounded the object that disappeared in a flash.
There is also the possibility that it doesn't go in a flash but gets absorbed slowly like being sucked through a pin hole leak into another area or time.
In some areas there might be planets or even stars that are being swiss cheesed ( cores of matter eaten by a black hole ) while the gravity of it is causing it to be trapped in a line type of orbit that is or is not perfect . If perfect the object will be fairly stable for a small amount of time as the mini black hole goes bouncing back and forth through the same hole until it all falls into itself . On the other hand if its off a little it would tend to eat the object up much faster taking new fresh bites till there is not enough mass to keep the black hole captured.
Its last bite would probably tend to slow down its movement in space and it would be less than noticeable to us at this time in our science knowledge. As the black hole was absorbing its meal there is less for it to eat and this would tend to put the brakes on it thus slowing down its travels to outer space into new areas . This would make me feel a little safer in our world . This might explain why these black holes are not traveling like crazy through space eating everything in its path ,they would appear to travel along with its host matter that is around it ,that helped it to form in the first place . This might explain why they say that black holes are feeding and not feeding . They feed when an object falls within its gravity and this upsets its movement in space then when it has mostly absorbed its matter just acquired it slows the upset and becomes stable again . This happens over and over as this eating process makes gravity waves that upsets the objects nearest to itself , causing more objects to get out of wack .
If black holes were moving through space at great speeds and numbers there would be evidence of missing material in gaseous nebulae ,They would look like dark straight lines of missing gas . The lines with time added would look like dashes in a swirling system . Do we see this anywhere in space , not yet ,i don't think but someone should be looking for this effect.
And another thing about mass and speed of its travel ,the faster it travels the more massive it becomes thats why matter to travel at near the speed of light would be nearly impossible . So matter traveling into a black hole approaching the speed of light would look more massive than it was originally ,this would tend to mean that just the small amount of matter in the vacuum of space is enough to generate the effect of a black hole as its just very small amounts of matter accelerating to near speed of light and appearing to be massive. How this all fits i think nobody knows !
But its here for us to figure out ! I haven't begun to even think about this on any great scale YET !
I would be interested in making an animation of these ideas and it might actually make more sense even to me. If i saw a movie of these ideas i might be able to see a new understanding of it all together or spark someone else to fitting it all together is a more likely thing to happen.
I would love to write sifi but with it pointing toward reality ,thats freaky enough !