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Mass/Energy of Relativistic Jets?

  1. Dec 19, 2013 #1
    Supermassive black holes sometimes have extended relativistic jets emerging from the poles. They are HUGE and powerful and fast.

    Has there been research into the mass of such jets? Any other impressive statistics about just how much mass and energy these things contain?
     
  2. jcsd
  3. Dec 31, 2013 #2

    Dotini

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    Jets are an enigma. The best we can do is refer you to a previous thread, easily findable through the tags function: https://www.physicsforums.com/showthread.php?p=4221199#post4221199
     
  4. Feb 13, 2014 #3

    Dotini

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  5. Feb 13, 2014 #4
    This article covers the jets in great and technical detail. Covers pretty much any measurable aspect of a black hole.

    Foundations of Black Hole Accretion Disk Theory

    http://arxiv.org/abs/1104.5499
     
  6. Feb 13, 2014 #5
    Thanks for the thoughtful replies. I'm downloading now.
     
  7. Feb 13, 2014 #6

    phyzguy

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    As I understand, we don't even know whether the energy of the jets is primarily baryonic, primarily leptonic, or primarily electromagnetic field energy.
     
  8. Feb 13, 2014 #7
    You might want to think about this statement as the electromagnetic spectrum includes both baryons (photons, neutrons) as well as leptons (electrons) .

    What is poorly understood on jets are the conditions that allow jets, when do they occur, what mechanism determine which objects can have jets? How do jet knots form? What % of the infalling matter converts to the energy and angular momentum ejected via the jets.
     
  9. Feb 13, 2014 #8

    phyzguy

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    I think you are confused on several points:

    (1) Photons are not baryons.
    (2) Neither neutrons nor electrons are part of the electromagnetic spectrum.
     
  10. Feb 13, 2014 #9
    lol your right I screwed up for some oddball reason I mixed up proton and photon. Also I poorly worded my reply in regards of neutron. I included it as an example of baryon.

    Not sure what I was thinking on this post must have been 3/4's asleep lol, long work day
     
  11. May 31, 2015 #10

    Dotini

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  12. May 23, 2016 #11
    I want to know if the accumulated mass of the jets could exceed the mass of the galaxy, and does this ejected mass included dark matter? Relativistic velocity would multiply the rest mass. With enough mass, this would profoundly affect the rotation of the galaxy and reduce reliance on a dark matter halo to explain the outer orbital velocities. If this has not been quantified, it remains a fascinating alternative explanation.
     
  13. May 23, 2016 #12

    mfb

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    It is a tiny fraction of the mass of the galaxy, and does not include dark matter.
    It does not. That's the point of "rest mass" (usually just called mass). It increases the energy, but not beyond the energy present before.
     
  14. May 23, 2016 #13
    If my word "profoundly" is not self-evident, let me elaborate. The ejected mass of the quasar jets have no effect at the center of the galaxy as the two jets presumably are symmetrical, have similar mass and cancel out. However, at any distance radially from the jet axis, their total mass is additive and gravitational "force" towards the axis increases proportional to the mass of the jets within a cylinder of that radius. Only after the expanding cylinder exceeds the total jet diameter does force completely transition to the inverse square law. Don't forget that the jets are conical and up to 14 billion lightyears long, so the width is significant.
     
    Last edited: May 23, 2016
  15. May 23, 2016 #14
    No. Mass increases with relative velocity. Relativistic velocity mass is significant. How is that incorrect? Jet velocities can exceed 0.999c and Lorentz factor of 40. If a modest 5% of the galactic mass were accelerated to 0.999c, the jets would outweigh the remaining galaxy.

    What I am looking for is the evidence one way or the other.
     
    Last edited: May 23, 2016
  16. May 23, 2016 #15
    ["tiny fraction"] Who has measured the accumulated mass of Quasar jets? Without measurements, where do we get any scale? (I don't see how human intuition can be relevant to start.)

    ["It does not"] Agreed. Dark matter has no charge, so it is not going be ejected by electromagnetic effects in the accretion disks. However, can we already be certain that dark matter has no self-interaction at extreme conditions near a spinning black hole?

    ["energy present before"] How much energy is available when all the hydrogen falls in from intergalactic-cluster distances? If the black hole and accretion disc has formed before the vast majority of the hydrogen arrives, how are we certain that the jets will not outweight the galaxy in the end?

    Would an expert on Quasar/Blazer jet mass please leave some links?
     
    Last edited: May 23, 2016
  17. May 23, 2016 #16

    mfb

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    Not with the meaning of "mass" that has been in use in the last ~80 years. No one uses the concept of a relativistic mass any more, apart from old textbooks and bad pop-science descriptions. "Mass" is always "rest mass".
    Baryonic matter is a small fraction of the total mass of galaxies. The central black hole is very small compared to the baryonic matter. And the jet mass (and also its energy) finally is small compared to the black hole mass. It has to be, everything else would violate conservation of energy.

    I don't see dedicated mass estimates, probably because no one cares - it is obvious to everyone writing publications about it that the mass is tiny.
    Why would the distance to a black hole matter for a local interaction?
    At most its mass multiplied by the speed of light squared. Most of that ends up in the black hole, however.

    Where is this going to? If you want to suggest jets would have some relevance on galactic rotation curves, please provide a peer-reviewed reference for that. Otherwise we cannot discuss it.
     
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