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What are the mechanism implications of MECO?

  1. Jul 5, 2010 #1
    What are the mechanism implications of MECO?

    I have been reviewing observational anomalies associated with quasars and spiral galaxy morophology/evolution and thinking about the MECO hypothesis and its implications. I would be interested in eventually discussing them as a set however I am having problems straightening out and organizing the related issues. I am hoping this thread and a second thread I will start later this month will help with that process.

    The MECO authors have been making headway to build an observational and theoretical case for the basic MECO model which is a massive compact object that has a very strong attached magnetic field. I have started this thread as a basic summary of the MECO authors’ work and suggest a comparison, pros/cons, similarities/differences: MECO model to the standard classic BH with an accretion disc.

    It seems to me that they have got to first base which is to provide sufficient observational evidence to support the assertion that the massive compact object has a massive magnetic field attached it.

    In addition to the very specific observational evidence provided in their papers there are a number of fundamental basic quasar observations that support their premise such as the discovery that roughly 10% of quasars are “Naked Quasars” whose spectrum does not include a broad line region type component. (The broad line region is assumed to be emissions from an accretion disc which is the energy source of the classical model. The broad line spectrum is due to the motion of the accretion disc.)

    I would suggest you differ reaching any conclusion as to what a MECO is (think of it as a class of possible models) in addition to the MECO Vs Classic BH accretion disk question until you have a chance to think about these specific observations and the observations in the next thread that I will start. (Try to pretend you are seeing the observations for the first time.)

    http://iopscience.iop.org/1538-3881/138/2/421

    http://arxiv.org/PS_cache/arxiv/pdf/0902/0902.1160v1.pdf

    This is additional specific analysis of two quasars to support their assertion.

    http://iopscience.iop.org/1538-3881/135/3/947

    Direct Mircolensing-reverberation Observations of the Intrinsic Magnetic Structure of Active Galactic Nuclei in Different Spectral States: A Tale of Two Quasars

    This is a good summary of the mechanism and theory.

    Does Sgr A* Have an Event Horizon or a Magnetic Moment?

    Stanley L. Robertson and Darryl J. Leiter

    http://journalofcosmology.com/RobetsonLeiter.pdf
     
  2. jcsd
  3. Jul 6, 2010 #2

    Chalnoth

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    We'll see in perhaps 5-15 years or so. There are some astronomers working on ultra long baseline interferometry to actually capture an image of the shape of the event horizon of the massive compact object at Sagittarius A*.

    As for a magnetic moment, yes, Sagittarius A* is sure to have a magnetic moment. No this isn't evidence for it being a MECO, as it is also expected from a black hole.
     
  4. Jul 6, 2010 #3
    http://arxiv.org/abs/astro-ph/0406163v1

    There is other observational evidence that the massive compact object has a strong attached magnetic field, for example the discovery of Naked Quasars, however, as I suggested let’s defer trying to making a simple choice of selecting the standard model or MECO.

    Let’s back track for a second and re-look at Disney et al’s paper.

    http://arxiv.org/abs/0811.1554

    I am not sure people are thinking about the theoretical implications of Disney et al’s discovery concerning spiral galaxies. There is evidence of controlled evolution of spirals and the spiral parameters. Rotational velocity is tightly controlled with multiple spiral parameters. There are two general spectral modes.

    There appears to be some fundamental mechanism that is missing. The mechanism in question must be able to control and affect multiple parameters in a spiral galaxy.

    Assume you did not have the classic BH with an accretion disc model. You were looking at the quasar and massive compact object observations as a set looking for observational evidence to construct a model.

    For example in Hawkins’ paper on time dilation of quasars and the first MECO paper quoted above it is noted that the massive compact object is creating long term semi cyclic patterns, with multiple periodicities out to around 2 years.

    We have specific assumptions about the massive compact object because we are thinking of the properties of the classical BH and because the quasar observations are not viewed as a set in an organized manner. Start from the observations, defer any theoretical model construction.

    Is the massive object compact stable with time? Are we observing something that builds and releases.

    The magnetic field of pulsars has been observed to increase with time rather than decrease. As there is no explanation for that observation it is ignored and contested. Are magtars the short term end of a process?

    The massive compact objects are observed to have a mass limit of around 10^10 solar masses (Fan’s quasar survey analysis). What is limiting both mass of the massive central object and spiral galaxies? We are looking for a link between something related to teh massive compact object and how it evolves to how the spiral galaxy evolves.


    http://www.physics.uci.edu/Cosmology/Fan_Xiaohui.pdf [Broken]

     
    Last edited by a moderator: May 4, 2017
  5. Jul 7, 2010 #4
    A MECO is not the same as a classical black hole. What are the other observations concerning massive compact objects?

    Another approach is to compare the MECO hypothesis (where "MECO" is defined to mean a class of models) to the observations and theory about other massive compact objects. For example "Anomalous X-ray pulsars (AXPs)".

    A fundamental difference in the MECO class of models is that the massive compact object is a physical object that has properties that change or could change with time depending on the specific model created. The MECO mechanism implications are we must look at the observations and then construct the model as opposed to the classic BH model.


    http://journalofcosmology.com/RobetsonLeiter.pdf


    http://arxiv.org/PS_cache/astro-ph/pdf/0307/0307133v1.pdf



    http://en.wikipedia.org/wiki/SGR_1806-20

    http://arxiv.org/PS_cache/astro-ph/pdf/0308/0308347v1.pdf

    Michel's summary paper was recommend as reading material at the end of magnetar presentation.

     
  6. Jul 7, 2010 #5

    Chalnoth

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    I am aware.

    Unfortunately this is a bit outside my field of study. However, a good rule of thumb with things like this is to take a "wait and see" approach until some really solid observations are available. The best that you've prevented so far is evidence that can be considered, "Yeah, I can sort of see how that might be reasonable," instead of a real smoking gun. When we get some extremely long baseline interferometry of Sagittarius A*, then we'll know for sure, one way or another.

    I will comment, however, that I've seen talks from people who are studying this sort of thing and still consider black holes as the only likely end result of gravitational collapse for sufficiently massive objects. I don't know whether that's because this solution of the Einstein equations hasn't received much publicity, whether it's considered highly speculative, or whether it's basically been shown to be wrong. In any case, a wait and see approach is warranted.
     
  7. Jul 8, 2010 #6

    Chronos

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    Observations affirmed by theory are less compelling than theory confirmed by observations. Prediction is the hallmark of any good theory. You can backfit most any set of observations to some sort of theory. Turning that theory into a predictive tool is the test.
     
  8. Jul 8, 2010 #7
    I agree a prediction is a valid test.

    What we are asking or should be asking is why has the problem not been solved todate (35 years of observations, some of the greatest minds on the planet working on the problem). The failure is due to faulty methodology. One cannot start with a guess theory/mechanism that was created before there were observations to provide some sort of guide to the correct mechanism/theory and then try to adjust the guess model to fit the observations, if the objective is to solve the problem.

    After 35 years there is no smoking gun support for a new mechanism and there are multiple sets of unexampled anomalies which are not discussed in standard text books (i.e. The text book includes the standard toy model that the specialists know cannot explain the observations however the toy model is easy to explain and can be used to produce simple examine questions, so it used and passed on.)

    There are fundamental problems: explaining blue stragglers, explaining the paradox of youth stars, pulsars and magnetars, metallicity variance in our galaxy and in other galaxies, quasar properties and quasar property variance with redshift, star burst galaxies, the spiral winding problem, Disney’s finding that spiral galaxies are simpler than expected, and so on. It appears there is some missing mechanism that is controlling spiral galaxies and details concerning stellar formation and stellar evolution in the spiral galaxies. Perhaps if one understood what that mechanism was then it would possible to explain why there is the observed morphological differences between spiral and elliptical galaxies, Disney’s observations concerning spirals, the evolution and morphological differences of spiral galaxies.

    If you review astrophysical observations at a detailed level (stars, galaxies, clusters and evolution of the same with redshift.) what is observed does not make sense. i.e. There are multiple anomalies. The anomalies seem to be connected. What is interesting about this field is there are detailed observational and theoretical model review papers that summarized in 30 to 40 page, 20 to 30 years of research.


    http://arxiv.org/PS_cache/astro-ph/pdf/0308/0308347v1.pdf
     
  9. Jul 8, 2010 #8

    Chalnoth

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    As with other things we've gone over here, there are large technical problems involved in properly simulating the physics of stars, especially compact stars like neutron stars. These technical problems prevent us from having that much confidence in our models of these stars in the first place. So it is difficult, at best, to pin a discrepancy on their behavior down to a misunderstanding of fundamental physics.
     
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