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Quasar Enigmas In 'decresing Light Speed' Cosmolog

  1. Sep 1, 2003 #1
    One of the main problems of quasars is: How can an energy equivalent to 100 times that of a normal galaxy, be produced continuously in a region smaller than the Solar System?

    To solve this puzzle, it was suggested that quasars were not at cosmological distances, but much closer, even within our Galaxy, although their redshift indicates that they are the farthest objects in the Universe. This controversy lasted for decades, but nowadays the evidence in favor of distant quasars is overwelming, so that understanding their fantastic power remains a challenge.

    Another suggested explanation was that collision with other galaxies was delivering extra amounts of gas to the central engine, large enough to sustain a quasar. But further observations revealed that a lot of quasars appear to reside in undisturbed galaxies (see http://www.stsci.edu/pubinfo/PR/96/35.html#Photos).

    An alternative explanation is provided by DeLightS model on the grounds of a decreasing speed of light. The main expected effect of time decreasing values of c on quasars is that as light slows down, the Schwarzschild radius of the black hole powering it will progressively increase. This will allow accelerated engulfment of material from the accretion disk; so should feed their axial jets of fast particles, increasing the energy emissions in all wavelengths in such a outstanding way.

    Furthermore, as the black hole mass increses, so does its radius, so that each of these effects helps each other in a synergistic way that allows a natural explanation of such a fantastic power output.

    Moreover, DeLightS implies that the amount of energy released by matter desintegration would be very much bigger in the ancient Universe than now. The amount of energy to be released per unit of mass absorbed should be roughly proportional to the total energy of that mass, and would be much higher if the well known equation E=mc2 is to be used with a higher value of c.

    As the Universe grows older, c decreases more slowly in DeLightS model, and the black hole expansion also moderates, and so do the radiation emissions. Then we observe AGN of moderate activity and finally ordinary galaxies with low nuclear activity even if their central engines are bigger and heavier than those of their preceding AGN. Weak or eventual quasarlike activity, such as X-Ray emission, in nearby galaxies indicate that they usually have dormant quasars in their centers.
  2. jcsd
  3. Sep 1, 2003 #2


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    You don't need the VSL model to explain quasars, in the glactic centre black hole model of quasars, blasars and radio galaxies (which we observe is dependent on our angle to them), there axial jets are fed by the occasional accretion of stars (which explains why we ponly see them occasionally). I've never seen anyone claim before that VSL can explain the light emitted by quasars.
  4. Sep 2, 2003 #3
    We do not see quasars ocassionally. Their wide range emission is continuous in time, although variable.

    If you read carefully, you will see that the basic mechanism proposed remains the standard one (feeding of supermassive black holes). What DeLightS helps to explain is how a such huge amount of energy is continuosly produced from a so small region and why quasars deactivate with time.

    DeLightS and VSL are not the same, although both involve a non-constant c.
  5. Sep 2, 2003 #4


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    In what way is VSL different from DelightS? I thought all cosmologies with a non-constnt c were VSL. The black hole will expand anyway by accretion, the standard AGN model explains why not all AGN are quasras/blazars/radio galxies and why quasars are so high-energy.
  6. Sep 2, 2003 #5
    VSL is an acronim from Magueijo to name his several theories on Variable Speed of Light. DeLightS is not one of them. In short DeLightS is an alternative model describing the dynamics of a flat Universe without cosmological constant and allowing a gradual change of c with time. New relationships of redshift vs. distance and cosmic background radiation temperature are given. Values for the Universal radius, matter density, Hubble parameter, light deceleration, cosmic age and recombination time are obtained. Distant SNeIa faintness is explained within this decelerating, matter-dominated Universe without invoking dark energy. Horizon, flatness and other problems of standard Big Bang cosmology are solved without the need of inflation. The top speed of any signal, particle or wave at any time is linked to the expansion speed of the Universe itself.

    What standard AGN model is not able to explain is how a quasar looses activity down to be a quiet, ordinary galaxy, even if its black hole has been growing by accretion. If I am wrong, let me know how it does.
  7. Sep 2, 2003 #6
    I think a quasar is NOT A BLACK HOLE
    but is two or more black holes orbiting eachother and moving very fast, therefor
    sweeping in alot more matter than a non moving black hole would or could.

    over time as the black holes get closer to forming a single black holes ie sink inside their event horizens, and quiet down

    or as black holes merge donot they gain mass, greater than the sum of the rest masses of each, so could some of the energy of the merger then power the quasar event?

    eithor way it is not just a black hole, but more than one that powers a quasar event and after the merger is completed the quasar is over
  8. Sep 2, 2003 #7


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    I've not heard of DeLightS, so I can't say to much about it.

    I think the AGN model of quasras doe stake into account that quasras may go quiet I know it ceratinly explains why not all AGNs are quasars/blazars/radio galaxies, IIRC it's the properties of the accretion disk that decide this.
  9. Sep 4, 2003 #8
    Here we have another explanation for quasar deactivation. Thanks for your contribution.
    Meanwhile jcsd eludes the question:

    Perhaps, but how?
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