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Most Distant Quasar a Theory Problem?

  1. Jun 30, 2011 #1

    Dotini

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    http://www.physorg.com/news/2011-06-astronomers-universe-distant-quasar.html

    The quasar that has just been found, named ULAS J1120+0641, is seen as it was only 770 million years after the Big Bang (redshift 7.1). It took 12.9 billion years for its light to reach us.

    These observations showed that the mass of the black hole at the centre of ULAS J1120+0641 is about two billion times that of the Sun. This very high mass is hard to explain so early on after the Big Bang. Current theories for the growth of supermassive black holes predict a slow build-up in mass as the compact object pulls in matter from its surroundings.


    Respectfully submitted,
    Steve
     
  2. jcsd
  3. Jun 30, 2011 #2

    bcrowell

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    Last edited by a moderator: May 5, 2017
  4. Jul 1, 2011 #3

    Chalnoth

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    This isn't a theory problem. It's a quasar problem. Basically, the physics of quasars are exceedingly complex and difficult to simulate. There is no reasonable way in which quasar observations could lead us to rewrite cosmology, just because our other observations, observations that do not require us to understand physics that is nearly as complex as quasar physics, give us extremely tight limits on the age and expansion of our universe.

    That said, quasar physics is itself extremely interesting.
     
  5. Jul 1, 2011 #4

    Dotini

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    http://www.scientificamerican.com/article.cfm?id=farthest-quasar
    To glow so brightly at that early epoch in cosmic history, the newfound quasar would have to be powered by a black hole roughly two billion times as massive as the sun, or 500 times the mass of the black hole at the center of our galaxy. But such heft requires an explanation. http://www.scientificamerican.com/article.cfm?id=baby-black-holes "The quasar itself is a remarkable object in that no one really knows how to form a black hole that massive, two billion solar masses, in what in cosmological terms is a relatively short time," Mortlock says. In other words, the astrophysicists have found the cosmic equivalent of a newborn baby with the stature of a full-grown adult. "It's essentially the hardest object to make in the early universe that we know about," Mortlock adds. The gargantuan black hole's existence, discovered through exhaustive telescopic observations, now becomes a challenge for theorists to address. "Assuming that the universe makes sense," Mortlock says, "it has to form somehow."

    Respectfully submitted,
    Steve
     
  6. Jul 1, 2011 #5

    Chalnoth

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    Yes, the people using simulations to understand the physics of quasars have a long way to go.
     
  7. Jul 1, 2011 #6
    Methinks thee spoke in haste...
    http://arxiv.org/abs/1106.6090"[/URL]
    [PLAIN]http://arxiv.org/abs/1106.6088"[/URL]
    ...:-)
     
    Last edited by a moderator: May 5, 2017
  8. Jul 1, 2011 #7
    Of course such a big, very young Black Hole might indicate that it's from before the Big Bang, which has been proposed recently...

    http://crowlspace.com/?p=1118"

    ...where I summarize the possibilities, with links to the arXiv preprints involved. Of course my speculations added to sober scientific theory are for entertainment purposes only ;-)
     
    Last edited by a moderator: Apr 26, 2017
  9. Jul 1, 2011 #8

    Chalnoth

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    The idea of primordial black holes is interesting, but it's highly, highly unlikely that primordial black holes have much of anything at all to say about supermassive black holes.
     
    Last edited by a moderator: Apr 26, 2017
  10. Jul 1, 2011 #9
    Want to put some references to that claim Chalnoth? Lots of different theorists have suggested PBHs act as seeds for nuclear black holes. Why are they mistaken?
     
  11. Jul 1, 2011 #10

    bcrowell

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    Cool, thanks for turning those up!

    The Willott commentary does a nice job of discussing the importance of the result for nonspecialists. There seem to be several proposed mechanisms for the formation of supermassive black holes: accretion, merging, and direct formation.
     
    Last edited by a moderator: May 5, 2017
  12. Jul 1, 2011 #11

    Chalnoth

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    Seeds, perhaps. But what I meant is that you still need a mechanism for the black holes to grow as large as they are. And having primordial black holes, as near as I can tell, doesn't help that in the least.
     
  13. Jul 1, 2011 #12
    I'm not claiming they're right - that requires actual data to confirm - but I'd like to know why you think it unlikely or wrong?
     
  14. Jul 1, 2011 #13
    Oh I see what you mean. Sorry my clarification came after your reply. I agree, thus the need to consider non-standard scenarios. Pre-Big Bang is just one suggestion. Others include Dark Stars and pseudo-stars.
     
  15. Jul 1, 2011 #14

    Chalnoth

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    Far and away the most likely answer is baryonic physics near black holes, not these exotic scenarios. The thing to understand here is that understanding the baryonic physics near black holes is extremely difficult, so much so that until we get a good handle on it, it isn't in any way reasonable to leap to conclusions.
     
  16. Jul 1, 2011 #15

    bcrowell

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    Can you point us to any good papers on this?
     
  17. Jul 1, 2011 #16
    But that's the safe and boring answer! You're right, of course, but the other possibilities are interesting enough to consider.
     
  18. Jul 1, 2011 #17

    Chalnoth

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    Right. Interesting, perhaps, but I tend to find the truth more interesting than wild speculation. And if you look at the physics that goes on around quasars, it is plenty interesting on its own. See here, for example: http://arxiv.org/abs/astro-ph/0502199
     
  19. Jul 1, 2011 #18
    Chalnoth, that is interesting, but I think the puzzle has arisen because that sort of model isn't up to the task.
     
  20. Jul 1, 2011 #19

    Chalnoth

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    Possibly. I'm not sure. Most of these issues get resolved through application of physics we already know. These are complex systems, as I mentioned, and that should be the default, go-to answer. And, as near as I can tell, that's what the majority of people working on quasars are looking at.

    Anyway, here's a video of the simulation pictured in that paper:


    Just posting that because it is really cool :)
     
    Last edited by a moderator: Sep 25, 2014
  21. Jul 2, 2011 #20
    Nice B-)
     
    Last edited by a moderator: Sep 25, 2014
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