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Galaxies formed from Quasars?

  1. Mar 31, 2013 #1
    Im wondering, if there is some theory, which is proposing that galaxies were formed from quasars?

    Or if not, are there some facts which are opposing such formation?
  2. jcsd
  3. Mar 31, 2013 #2


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    A quasar is believed to be an actively feeding supermassive black hole. Such a feeding frenzy is probably unlikely until galaxy formation is well underway.
  4. Mar 31, 2013 #3
    Yes, but Im not sure if this is answer to my question.

    Both galaxies and quasars probably have supermassive black hole in the center. The question is, could it be possible, that over time quasars evolve into standard rotating galaxies?

    Is there some theory which is predicting such evolution? I personally do believe, that supermassive black hole in center of quasar decreases feeding and gravitational pull over time and then it evolves into standard galaxy. Now Im searching for theories which would either predict something similar or are ruling it out.
  5. Mar 31, 2013 #4
    Good luck but you wont find any theory that a supermassive blackhole will eventually collapse into a galaxy. For that matter the only theory that suggests blackholes can ever evaperate is by Hawkings radiation. That process would take longer than the age of the universe.

    However the gravitational influences of blackholes may assist galaxy formation.
    Last edited: Apr 1, 2013
  6. Apr 1, 2013 #5
    So let's take an extremely fast spinning Kerr black hole with a large mass M, how long does it take to evaporate for a given background temperature?
  7. Apr 1, 2013 #6
    A 1 solar mass blackhole would take roughly 2.0*10^67 years


    Im not sure how the calculations would apply on a fast spinning kerr BH offhand.
  8. Apr 1, 2013 #7
    For a fast spinning Kerr black hole or a Schwarzschild black hole?
  9. Apr 1, 2013 #8
    The figute above is Shwartzchild non rotating
  10. Apr 1, 2013 #9
    1. Would you agree that most (if not all) black holes in our universe spin?
    2. Would you agree that experimental data seems to indicate that they spin rather quickly?
    3. Then would it not follow that we should use the evaporation formula for a fast rotating black hole instead of a Schwarzschild black hole?
    4. If it turns out that we actually do not have a good evaporation formula for a fast rotating black hole and that all we have is a Kerr black hole without an interior solution should we exclude the possibility that fast rotating black holes can evaporate much faster based on the fact that Schwarzschild black holes take a very long time to evaporate?
  11. Apr 1, 2013 #10
    I understand what your asking. I have read a few articles debating that very question. One believe is that kerr blackholes eventually form Schwartchild blackholes. Other papers such as this one describe otherwise.


    most solutions Ive seen involve converting the evaperation energy to a shwartzchild leading to similar evaperation rates. However its not an area Ive studied in depth. Its something Im currently working on.
  12. Apr 1, 2013 #11
    Thanks for response and for insight regarding current theories regarding this topic.

    I have my very own crackpot gravity theory which is extending general relativity and one of the predictions of this theory is that apart from Hawking radiation there is also an additional source of decreasing gravity of fast rotating supermassive black holes. This would lead into transformation of quasars to galaxies and it would also explain galaxy rotation problem.

    But what I understand, because of forum rules, Im not allowed to present my theory here, so Im just explaining why Im asking this question.
  13. Apr 1, 2013 #12
    That article above is a 1998 article. If you google Kerr blackhole evaperation. You will be able to find numerous papers. Do the same at the arxiv site for current proposols.

    This article may assist your research. It has a compiled list of formulas regarding accretion disk measurements.

  14. Apr 1, 2013 #13


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    Quasars are a result of the formation of galaxies. It doesn't even make sense to talk about a galaxy forming from a quasar, any more than it makes sense for a solar system to form from a planet.
  15. Apr 1, 2013 #14
    I doubt that this solar system example is relevant. Solar system evolved around Sun in the center, not around planet.
    But both quasars and galaxies have in the center supermassive black holes and all evolved around of these supermassive black holes. But the question is as following: Is it possible, that quasars are only an early stage in evolution of rotating galaxies?
  16. Apr 1, 2013 #15


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    The reason why I used a planet as the example in the analogy is because the supermassive black holes at the centers of galaxies tend to be, at most, a few percent of the galaxies' mass. The Sun, on the other hand, contains nearly all of the mass of our solar system. So a quasar is much more like Jupiter in the analogy: significant impact on the structure of the solar system (e.g. by preventing the planet that tried to form in the asteroid belt from actually forming), but a small fraction of the total mass, and in no sense the cause of the solar system forming in the first place.

    Quasars are what happens when the nuclei of galaxies gobble up matter. This happens when galaxies first form, and can also happen when galaxies collide.
  17. Apr 1, 2013 #16
    OK, understanding it now, thanks for explanation.
  18. Apr 1, 2013 #17
    Quasars are part of a galaxy, they're they're just the active galactic nucleus of a SMBH gobbling up matter. Eventually they will fizzle out, whether it's the energy output pushing material away, or there's "no more stuff" to eat... in which case a quasar becomes a non-active galaxy kind of like the Milky Way, which could have been a quasar in the past (or at the very least some type of other active galaxy)
  19. Apr 1, 2013 #18


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    Indeed, there's evidence of jets streaming from the center of our own galaxy that indicate that our black hole may have been active as recently as 20,000 years ago:
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